WO2022214423A1

WO2022214423A1 - Maternity bra

Info

Publication number: WO2022214423A1
Application number: PCT/EP2022/058853
Authority: WO
Inventors: Komkrit SAJJAANANTAKUL; Arunwat PROMNIMIT; Wanattha RIANKHIAO; Thanyamas HUAYHONGTONG
Original assignee: HAYDALE TECHNOLOGIES (Thailand) Company Limited; Haydale Graphene Industries Plc
Priority date: 2021-04-05
Filing date: 2022-04-04
Publication date: 2022-10-13

Abstract

The present invention relates to a heatable maternity bra comprising a bra body connecting two cups, wherein at least one cup includes a fabric with a heatable section comprising graphene particles dispersed in a polymer matrix material, as well as to a heatable maternity bra insert for inserting into a cup of a heatable maternity bra, their methods of manufacture, and their uses in methods of treating a postpartum subject.

Description

MATERNITY BRA

FIELD OF THE INVENTION

The present invention relates to underwear, in particular to bras and most particularly maternity bras.

BACKGROUND

After giving birth nursing mothers may experience a variety of problems associated with breastfeeding. These include the delayed onset of milk production (known colloquially as “milk coming in”), and/or they may produce only small quantities of milk. These problems may lead to concerns about whether the baby has enough milk. Additionally, many nursing mothers experience nipple pain.

Heat treatment of the breasts of nursing women can be used to increase blood flow to the breast area, increase milk production in the cells of the breast, increase the levels of the hormone prolactin in the blood and increase the permeability of prolactin to the cells. This can lead to more efficient milk production and earlier onset of milk production after birth.

For example, Panngam et al. “Effects of Breast Compress with Polymer Gel Compress on the First Lactation in Mothers after First Pregnancy" studies the onset of milk production in first time mothers. The subjects were split into two groups (1) subjects who applied heated polymer gel compresses to their breasts and (2) a control group who nursed regularly but did not apply polymer gel compresses. The polymer gel compresses used were developed by a researcher in consultation with a heat treatment specialist. The polymer gel compresses were immersed in water at 70 - 80 °C for 5 minutes to heat the compress. The subjects in group (1) applied the breast compress for 20 minutes and the temperature of the tissues during use of the compress was measured with a thermal imager. The results showed that the temperature level of the polymer gel sheets in the compress was between 38-56 °C without any risk or complications to the volunteers.

The results of this study showed that first time mothers, after giving birth, who used the heated polymer gel compresses, have earlier onset of milk production than mothers who did not apply the compresses. This demonstrates that using gel polymer ball breast compresses, with a temperature between 38.3-47.3 °C over the period of 20 minutes, causes easing in the muscles of the artery wall, leading to expansion of the blood vessels. Also, heat helps reduce the viscosity of the blood. As a result, blood flows to the breast and the cells produce more milk. In addition, the heat increases the activation of the 10 genes in the milk production process, leading to higher efficiency in the process of milk production and secretion.

The application of heat to the breasts is also known to reduce pain associated with breast feeding including breast tightness and pain in the nipple. For example, Buchko et al. “Comfort Measures in Breastfeeding, Primiparous Women” reveals that after mothers gave birth, they often experience pain in the nipples and breasts while breastfeeding. Some mothers experience sore nipples to the extent that bleeding occurs and therefore stop breastfeeding prematurely. Researchers were interested in ways to relieve sore nipples or to prolong breastfeeding for babies' health. An experiment was carried out with groups of breastfeeding mothers aged over 18 years, who had low-risk pregnancies and gave birth after 37 gestation without complications. The mothers were divided into 4 groups, who all used different treatments for relieving nipple pain. Group 1 used tea bags, Group 2 used warm water, Group 3 massaged the nipples, and Group 4 uses dried herbs. The results showed that warm water compress was the best of these methods for relieving sore nipples of mothers after childbirth.

A 2011 research study from Ban Chang Hospital in Thailand on the effect of breast compress massage on maternal milk flow after childbirth on cognitive level shows that the average intelligence of Thai children is relatively low due to the low duration of breastfeeding. Most of these problems arise from the lack of flow or low volume of milk. Therefore, groups of nursing mothers were compared who used a heated breast compress to massage the breast and a group who breastfed their babies normally. The results show that in the group making use of the breast compress, the milk began to flow in the first hour after birth and had improved 16 hours after birth, in comparison in the group who did not use the breast compress, milk began to flow in the eighth hour after birth and improved 48 hours after birth.

However, using compresses to warm the breasts is time consuming as these compresses generally must be heated up in warm water. Additionally, the compresses must be manually held on to the breast which is awkward and impractical for a nursing mother. Further, it is difficult to accurately control the temperature of the compresses, leading to potential problems of burning of the skin if the temperature becomes too high, or reduced effectiveness if the temperature is too low.

There remains a need to develop improved products and methods for accelerating onset of milk production, increasing the amount of breast milk production and reducing nipple pain for breastfeeding mothers.

SUMMARY OF THE INVENTION

The present inventors have worked to provide a solution to the above problems. The present inventors considered the option of a wearable piece of clothing such as a maternity bra that could be heated, to help address the practical problems of compresses. Heatable garments are known from e.g. WO 2017/129663 A1. This application proposes using graphene to heat garments although has a particular focus on sportswear to which different considerations apply compared to underwear. Chinese utility model CN 210809343 U discloses the concept of a nursing bra comprising graphene. However, this document fails to provide concrete details about the graphene itself. For example, nothing is taught about how to incorporate the graphene into any particular layer, what properties might be suitable, or what variables would enable a user to achieve all of the alleged benefits.

Broadly, the present inventors have discovered that graphene can be efficiently used in a maternity bra to provide relief and improve milk production and quality in breastfeeding mothers.

Accordingly, in a first aspect the present invention provides a heatable maternity bra comprising a bra body connecting two cups, wherein at least one cup includes a fabric with a heatable section comprising graphene particles dispersed in a polymer matrix material.

In a second aspect the present invention provides a heatable maternity bra insert for inserting into a cup of a heatable maternity bra, the insert comprising a fabric with a heatable section comprising graphene particles dispersed in a polymer matrix material. Accordingly, the present proposals also encompass a heatable maternity bra comprising at least one of those bra inserts. The heatable maternity bra may be according to the first aspect.

In another aspect, the present invention provides the use of a heatable maternity bra or of an insert according to the above aspects, in a method of stimulating breast milk production in a postpartum subject.

In a still further aspect, the present invetnion provides the use of a heatable maternity bra or of an insert according to the above aspects, in a method of treating lactation insufficiency in a postpartum subject.

In a still further aspect, the present invention provides a method of stimulating breast milk production in a postpartum subject, the method comprising applying a heatable bra or an insert according to the above aspects, to at least one breast.

In a still further aspect, the present invention provides a method of treating lactation insufficiency in a postpartum subject, the method comprising applying a heatable bra or an insert according to the above aspects, to at least one breast.

In a still further aspect, the present invention provides a method of manufacture of a heatable maternity bra or of an insert according to the above aspects, the method comprising: a) providing a sheet of frabric; and b) depositing one or more layers of graphene particles dispersed in a polymer matrix material onto at least a portion of the fabric.

The term “maternity bra” is used herein to refer to a bra (alternatively referred to as a brassiere) which is intended or suitable for use by a woman producing milk or colostrum, such as a pregnant or postpartum woman. Preferably, the maternity bra is a nursing bra. A nursing bra is intended or suitable for women who are breastfeeding or expressing milk or colostrum. In general, such bras are configured to allow convenient and comfortable breastfeeding / expressing without the need to remove the bra. This can be accomplished by any standard means known in the art and includes but is not limited to bras having cups capable of being opened e.g. with one hand, to expose the nipple.

By “bra body”, we mean the clothing material which forms the structure of the bra, e.g. one or more fabric panels which are connected (e.g. stitched) together into a bra.

As is known in the art, a bra includes two cups which are applied to the breasts in use. Accordingly, it follows that “cup region” refers to a section of the cup of the bra.

A heatable maternity bra according to the invention may optionally contain any other standard components of a typical maternity bra, such as straps and clips and the like.

Such will not be particularly discussed in detail here.

The heatable maternity bra according to the present invention has a number of advantageous features.

Firstly, the heatable maternity bra according to the present invention is flexible as low loadings of graphene particles can be used. This means that the mechanical properties of the heatable section can be dominated by the relatively more flexible matrix material, instead of the less flexible graphene particles. The small size of the graphene particles also lessens the impact of the particles on the mechanical properties of the heatable section compared to relatively larger particles.

This also means that the heatable maternity bra can be washed without compromising its heating ability. It is important that maternity and especially nursing bras can be washed regularly, as leaked milk can lead to a build-up of bacteria in the bra. Without wishing to be bound by any theory it is believed that the use of graphene, which allows the properties of the heatable section to be dominated by the matrix material, provides greater flexibility and thereby the maternity bras of the invention are able to better withstand tumbling within the drum of the washing machine. Furthermore, the flexibility means that they can open more easily at the front of the maternity bra to allow nursing, without wear or fatigue. Secondly, the present arrangement helps the heatable section to flex and adapt to deformation of the maternity bra, whilst keeping the heatable section in close proximity to the breast.

Thirdly, construction of the heatable maternity bra is relatively simple. For example, the present construction avoids the need to form conductive fibres into the fabric of the bra itself and avoids the need to form separate pouches or pockets for incorporation of a heatable section. This is particularly advantageous in a maternity bra, at least for reasons of aesthetics and comfort.

Fourthly, the graphene- based heatable section can have a rapid temperature response to applied voltages and good heat stability, even when flexing. For example, the inventors have found that embodiments of the graphene- based heatable section as used in the present invention can settle at an equilibrium temperature after approximately 20 seconds and will cool down within seconds of the voltage being removed. This is believed to be most probably due to the excellent thermal conductivity properties of the graphene nanoparticles.

Fifthly, the uniformity of heat distribution of a graphene-based heatable section compared to that of a traditional serpentine wire heater is improved, due to the ability to provide more even/uniform heat to an area. This again allows for a safer and more controlled application of heat for use upon the breast, as it reduces the likelihood of the formation of hot spots.

Furthermore, the power requirements of the heatable section are relatively low, due to the excellent electrical and thermal properties of the graphene particles dispersed in the polymer matrix material. This means that the maternity bra can be powered using small, lightweight (and hence easily transportable), long-lasting power supplies, thus improving the “wear-ability” and usability of the bra. This is particularly important for maternity bras, where it may be advantageous to be able to use them “on the move” for example at a coffee shop or playgroup where nursing mothers may want to feed their babies. Therefore, the present heatable maternity bra has benefits over previous systems as it is portable.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a schematic diagram of a heatable maternity bra according to the present invention.

Figure 2 shows a schematic cross-sectional diagram of a cup of a heatable maternity bra according to the present invention.

Figure 3 shows the results of tests used to determine the amount of milk produced with and without the use of a heatable maternity bra according to the present invention.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference to preferred embodiments and other optional features. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although, any methods and materials similar or equivalent to those described herein can be used in practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below. Unless clearly indicated otherwise, use of the terms "a," "an," and the like refers to one or more.

While the invention is described in conjunction with the exemplary embodiments described below, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments set forth herein are considered to be illustrative and not limiting. Various changes may be made without departing from the scope of the invention which is defined by the claims. All references referred to herein are hereby incorporated by reference.

Each and every compatible combination of the embodiments described herein is explicitly disclosed herein, as if each and every combination was individually and explicitly recited. Additionally, where used herein, “and/or” is to be taken as a specific disclosure of each of the two specified features with or without the other.

Unless context dictates otherwise, the descriptions and definitions of the features set out herein are not limited to any particular aspect or embodiment and apply equally to all aspects and embodiments which are described where appropriate.

Where values are described as “at most” or “at least” it is understood that any of these values can be independently combined to produce a range.

Unless indicated otherwise, values provided are generally recorded at room temperature, that is, within the range 20-30°C for example 20°C.

Where non-SI units are provided, it will be understood that these can be converted easily into SI units by the skilled person.

The use of headings herein is intended to be to assist the understanding of the invention by the reader and does not imply any limitation on the invention as defined in the claims. Heatable Section

In this application, we generally refer to “a heatable section” or “the heatable section” which, although singular, is not meant to imply any limitation to “one” heatable section. That is, the heatable maternity bra of the present invention can comprise one or more heatable sections (i.e. one or more regions of fabric comprising graphene particles dispersed in a polymer matrix material). The number of heatable sections is not particularly limited. Typically, a heatable maternity bra according to the invention will have at least one heatable section per cup. Preferably, a heatable maternity bra according to the invention will have one or two heatable sections per cup.

The heatable section may take the form of a line, sheet, or patch extending across the surface of the bra cups. The surface area may be for example 20 cm² or more, 30 cm² or more, 40 cm² or more, 50 cm² or more, or 60 cm² or more. Typically, the surface area of the heatable section may vary according to cup size. If more than one heatable section is present, the surface area may refer to the total surface area per cup. If more than one heatable section is present, the form of the heatable section may be the same or different. Typically, where a heatable section is present per cup of a maternity bra, the heatable sections may have reflected symmetry.

Preferably, the heatable section is a heatable ink or coating bonded (directly or indirectly) to the fabric of the heatable maternity bra. A heatable section in the form of a heatable coating or ink can be made relatively thinner than a heatable section in the form of a molded article which is subsequently adhered to the maternity bra. Advantageously, decreasing the thickness of the coating or ink helps to improve flexibility and stretchability. Preferably, the heatable coating or ink is bonded directly to the fabric of the maternity bra, since this results in a particularly compact construction. This is advantageous form the point of view of comfort and aesthetics for nursing mothers.

Particularly, the inventors find that screen printing a graphene-based (graphene-containing) ink onto a fabric is particularly suitable in the present invention.

Most preferably, the heatable section is or comprises one or more layers of an electrically conductive ink comprising graphene particles in a polymer matrix material which has been applied (e.g. screen printed) to a region of a cup of the maternity bra. Preferably the conductive ink is applied directly to fabric because the ink, when cured, adheres directly to the fabric surface without the need for a separate adhesive. Advantageously, maternity bras in which a conductive ink is applied directly to fabric can be made relatively compact, and hence can have minimal impact on the mechanical properties of the maternity bra. Furthermore, the heatable section can be formed by applying the ink to the area of interest, which is relatively straightforward compared to having to manufacture a separate part in the desired shape and size, before applying to the maternity bra. The graphene-based ink produces heat through resistive heating upon application of an electrical current. The amount of heat generated is determined by the relationship: power =

Y/R.

To achieve safe and useful temperatures from suitable power supplies, the heatable section typically has a resistance of 500 W or less, 400 W or less, 300 W or less, 200 W or less, 150 W or less, and preferably 100 W or less, 75 W or less, 50 W or less, 40 W or less, 30 W or less, 20 W or less, 15 W or less, or 10 W or less. Advantageously, smaller resistances require lower voltages to achieve a desired power level, and hence can run off a low voltage battery supply, which can improve safety and reduce the weight and bulk of the bra. Typically, this resistance is measured at 50 microns thickness.

The sheet resistance of the heatable section may be, for example, 50 W/square or less, 40 W/square or less, 30 W/square or less, or 20 W/square or less. Preferably, the sheet resistance is from 4 to 50 W/square, or from 5 to 30 W/square, or from 7 to 20 W/square, most preferably between 10 and 16 W/square. Typically, sheet resistance is measured at a thickness of 50 microns.

The heat conduction values may be up to 3 Amperes, such as 2.5 Amperes or less or 2 Amperes or less. The lower limit is not particularly limited, and may be 0.1 Amperes or more, such as 0.3 Amperes or 0.4 Amperes. Preferably, the heat conduction is between 0.4 and 3 Amperes.

In the present invention, the heatable section may comprise a single layer of conductive material, or formed from multiple stacked layers (e.g. 2, 3, 4 or 5) of conductive material. Coating/printing multiple stacked layers to form the heatable section can result in a more uniform thickness (and hence more uniform heating) than coating/printing a single layer of the same overall thickness.

The average (mean) thickness of the heatable section (i.e. mean distance between a bottom surface and a top surface of the graphene particles dispersed in the polymer) may be, for example, less than 300 pm, less than 200 pm, less than 150 pm, preferably less than 100 pm or less than 75 pm. The lower limit for the average thickness may be, for example 1 pm, 3 pm,

5 pm or 10 pm. Preferably, the average thickness is 1 to 100 pm, more preferably 1 to 75 pm.

In instances where the cup region comprises multiple layers, each layer may have a maximum average thickness of, for example, 50 pm, 25 pm, 15 pm, 10 pm or 5 pm. The minimum average thickness may be, for example, 0.5 pm, 1 pm, 3 pm or 5 pm. Preferably, the average thickness of each layer is 1 to 15 pm. Advantageously, such thicknesses allow the cup region to be easily deformable and provide sufficient resistance for the required heating whilst allowing a relatively thin device to be produced. Graphene particles

The maternity bra of the present invention comprises a fabric that has graphene particles dispersed in a polymer matrix material. The graphene particles are conductive and allow heating through resistive (Joule) heating.

The graphene particles may be randomly dispersed in the polymer matrix material. Providing carbon in this form instead of, for example, in the form of woven carbon microfibre sheets encased within a polymer matrix material, simplifies manufacture and reduces expense. Furthermore, the conductivity of graphene particles (which is higher than, for example carbon black and graphite) means that a conductive heatable section can be formed at relatively low loadings. In addition, using carbon particles in this form allows the graphene-containing composition to be applied to the fabric using coating (e.g. printing) techniques, which simplifies manufacture compared to use of woven carbon microfibre, particularly when used to form complex shapes.

Suitably, the graphene particles have a high aspect ratio. Advantageously, graphene particles having a high aspect ratio can form conductive paths at relatively low loading levels, helping to improve the flexibility.

The graphene particles (which can be referred to as “graphene-material particles”, or “graphene- based particles”) may take the form of monolayer graphene (i.e. a single layer of carbon) or multilayer graphene (i.e. particles consisting of multiple stacked graphene layers). Multilayer graphene particles may have, for example, an average (mean) of 2 to 100 graphene layers per particle. When the graphene particles have 2 to 5 graphene layers per particle, they can be referred to as “few-layer graphene”.

Advantageously, these forms of carbon nanoparticles provide extremely high aspect ratio conductive particles. This high aspect ratio allows the formation of conductive paths at relatively low loading levels, decreasing the volume occupied by the carbon nanoparticles and thus increasing flexibility/stretchability.

The graphene particles may take the form of plates/flakes/sheets/ribbons of multilayer graphene material, referred to herein as “graphene nanoplatelets” (the “nano” prefix indicating thinness, instead of the lateral dimensions).

The graphene nanoplatelets may have a platelet thickness less than 100 nm and a major dimension (length or width) perpendicular to the thickness. The platelet thickness is preferably less than 70nm, preferably less than 50 nm, preferably less than 30 nm, preferably less than 20 nm, preferably less than 10 nm, preferably less than 5 nm. The major dimension is preferably at least 10 times, more preferably at least 100 times, more preferably at least 1,000 times, more preferably at least 10,000 times the thickness. The length may be at least 1 times, at least 2 times, at least 3 times, at least 5 times or at least 10 times the width. The loading of graphene particles in the polymer matrix material may be, for example, 0.25 wt.% or more, 0.5 wt.% or more, 1 wt.% or more, 2 wt.% or more, 5 wt.% or more, 10 wt.% or more, 15 wt.% or more, 20 wt.% or more, 30 wt.% or more, 40 wt.% or more, 50 wt.% or more or 60 wt.% or more of the total weight of the dispersion comprising graphene particles and polymer matrix material. The upper limit for the loading of graphene particles in the polymer matrix material may be, for example, 1 wt.%, 2 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, 50 wt.%, or 60 wt.% or 70 wt.%. If the loading of graphene particles is too low then the resistance of the fabric will be high, necessitating greater voltages to achieve a desired temperature. If the loading is too high, then this can adversely affect the mechanical properties of the fabric (in particular, flexibility and stretchability), and hence the mechanical properties of the maternity bra. For these reasons, it is preferable for the loadings of the graphene particles to be in the range of, for example, 5 to 50 wt.%, 10 to 40 wt.%, or 20 to 40 wt.%. Most preferred is 1 to 10 wt%.

The graphene particles are preferably uniformly dispersed throughout the polymer matrix material since aggregates (clumps) of material may decrease the uniformity of heating of the heatable section in use. However, it is not straightforward to achieve a suitably uniform dispersion of graphene particles since such particles have a powerful tendency to agglomerate and are difficult to disperse in solvents and polymer materials.

Particularly preferably, the graphene particles are functionalised graphene particles, e.g. functionalised graphene, or functionalised graphene nanoplatelets. That is, the graphene particles incorporate functional groups which improve the affinity of the nanoparticles for the solvents and/or polymer matrix material used in the present invention, thus allowing a more uniform distribution of particles to be achieved. For example, the graphene particles may be oxygen-functionalised, hydroxy-functionalised, carboxy-functionalised, carbonyl-functionalised, amine-functionalised, amide-functionalised, or halogen-functionalised. The graphene particles may be amine, amide or halogen functionalised.

Preferably, the functional groups present on the surface of the graphene particles are hydroxyl, carboxyl, carbonyl, amine, amide or a mixture of these functionalities. Most preferred are amine and/or amide functional groups.

Preferably, the functionalised graphene particles are plasma-functionalised graphene particles (i.e. particles which have been functionalised using a plasma-based process). Advantageously, plasma-functionalised graphene particles can display high levels of functionalisation, and uniform functionalisation.

Any suitable type of functionalisation process can be used to achieve the desired functionalisation. However, preferably, the surface functionalised graphene particles are plasma-functionalised graphene particles (i.e. graphene particles which have been functionalised using a plasma- based process). Advantageously, plasma-functionalised graphene particles can display high levels of functionalisation, and uniform functionalisation. Using a plasma-based process to functionalise the graphene particles leads to a reduced level of damage to the structures of the particles compared to wet chemistry methods and allows bespoke functionalisation of the particles and avoids the presence of impurities. For example, the Hummers’ method used to generate graphene oxide can introduce metallic impurities (especially manganese from the catalyst used), as well as sulphur impurities (from the sulphuric acid used in the production process). Preferably, the surface functionalised graphene particles according to the present invention comprise less than 1% sulphur, less than 0.5% sulphur, less than 0.2% sulphur, or less than 0.1% sulphur, as assessed by elemental analysis. Likewise, the amount of metallic impurity may be less than 0.5%, less than 0.2%, or less than 0.1 % on an elemental basis.

In particular, the inventors have found that when graphene particles are prepared using agitation in low-pressure plasma, such as described in WO 2010/142953 and WO 2012/076853, they are readily obtained in a format enabling dispersion in solvents and subsequently in polymer matrices, or directly in polymer melts, at good uniformity and at levels more than adequate for the purposes set out above. This contrasts with conventional processes for separating and functionalising graphene particles, which are extreme and difficult to control, as well as damaging to the particles themselves.

Specifically, the starting carbon material - especially graphitic carbon bodies - is subjected to a particle treatment method for disaggregating, de-agglomerating, exfoliating, cleaning or functionalising particles, in which the particles for treatment are subject to plasma treatment and agitation in a treatment chamber. Preferably the treatment chamber is a rotating container or drum. Preferably the treatment chamber contains or comprises multiple electrically conductive solid contact bodies or contact formations, the particles being agitated with said contact bodies or contact formations and in contact with plasma in the treatment chamber.

The particles to be treated are carbon particles, such as particles which consist of or comprise graphite, or other nanoparticles.

Preferably the contact bodies are moveable in the treatment chamber. The treatment chamber may be a drum, preferably a rotatable drum, in which a plurality of the contact bodies is tumbled or agitated with the particles to be treated. The wall of the treatment vessel can be conductive and form a counter-electrode to an electrode that extends into an interior space of the treatment chamber.

During the treatment, desirably glow plasma forms on the surfaces of the contact bodies or contact formations.

Suitable contact bodies are metal balls or metal-coated balls. The contact bodies or contact formations may be shaped to have a diameter, and the diameter is desirably at least 1 mm and not more than 60 mm. The pressure in the treatment vessel is usually less than 500 Pa. Desirably during the treatment, gas is fed to the treatment chamber and gas is removed from the treatment chamber through a filter. That is to say, it is fed through to maintain chemical composition if necessary and/or to avoid build-up of contamination.

The treated material, that is, the particles or disaggregated, deagglomerated or exfoliated components thereof resulting from the treatment, may be chemically functionalised by components of the plasma-forming gas, forming e.g. carboxy, carbonyl, hydroxyl, amine, amide or halogen functionalities on their surfaces. Plasma-forming gas in the treatment chamber may be or comprise e.g. any of oxygen, water, hydrogen peroxide, alcohol, nitrogen, ammonia, amino-bearing organic compound, halogen such as fluorine, halohydrocarbon such as CF_4, and noble gas.

Any other treatment conditions disclosed in the above-mentioned WO 2010/142953 and WO 2012/076853 may be used, additionally or alternatively. Other means of functionalising and/or disaggregating carbon particles may be used for the present processes and materials, although we strongly prefer plasma-treated materials.

For the present purposes the type and degree of chemical functionalisation of the graphene particles is selected for effective compatibility at the intended loadings with the selected polymer matrix material. Routine experiments may be effective to determine this.

Additional Fillers

Other forms of conductive particle filler may be used alongside the graphene particles. The conductive particle filler is not particularly limited, for example, the fabric of the cup region may further comprise carbon fillers or metal particles (e.g. silver particles).

Preferably, the loading of conductive particle filler in the polymer matrix material is from 0.5 - 20.0 wt.%, more preferably from 0.5 wt.% to 15 wt.%, most preferably from 1.0 wt.% to 10.0 wt.%.

Preferably, the conductive particle filler is a carbon filler. The carbon filler is generally a particulate carbon material. This may be any type of carbon based material, such as carbon black, acetylene black (ACB), carbon nanotubes (single walled, or multiwalled), carbon nanorods, or graphitic platelets.

In some embodiments, the carbon filler comprises carbon black and/or acetylene black (ACB- which is sometimes considered to be a specific type of carbon black). The use of these materials as carbon fillers gives primers with high levels of conductivity at low costs. The use of compositions comprising carbon black may be relatively low cost in comparison to other forms of carbon filler. Examples of carbon black include channel black, furnace black, lamp black or thermal black. Carbon black is generally obtained by the incomplete combustion of heavy petroleum products, for example FCC tar, coal tar or ethylene cracking tar. It may have a paracrystalline or amorphous structure, and may be acidic, neutral or basic. Carbon black is commercially available, for example as CABOT BP 2000, Degussa Printex XE-2B Mitsubishi MA-7 and Orion FW 200. In other embodiments, fillers other than carbon black may be useful.

The carbon filler may be surface functionalised. Without being bound by any theory it is thought that this helps to achieve high conductivities and high dispersal in the polymer matrix. The carbon filler may be oxygen-functionalised, hydroxy-functionalised, carboxy-functionalised, carbonyl-functionalised, amine-functionalised, amide-functionalised, halogen functionalised or silane functionalised or a hybrid of one or more of these types of functionalisation.

Any suitable type of functionalisation process can be used to achieve the desired functionalisation. However, preferably, the surface functionalised carbon filler is a plasma- functionalised carbon filler (i.e. carbon particles which have been functionalised using a plasma- based process).

The surface functionalised carbon filler may comprise at least 0.1 %, or at least 1%, or at least 5 % or at least 10 % elements other than carbon based on the total weight of carbon filler (based on elemental analysis). The maximum amount of elements other than carbon may be, for example, 20%, 30% or 40% based on the total weight of the carbon filler (based on elemental analysis).

Preferably, the carbon filler particles have a volume average mean particle size of less than 10 pm. Volume average mean particle size can be determined using any suitable method known to a skilled person in the art such as light scattering (mean size = mean hydrodynamic diameter of the particles) or laser distribution particle size. Preferably, light scattering is used. Light scattering can be measured using a light scattering analyser e.g., dynamic light scattering particle size distribution analyzer LB-550 (available from HORIBA).

The weight ratio of graphene particles to carbon filler in the polymer matrix material is preferably 10:1 - 1:10, more preferably 1:5 - 5:1, more preferably 1:2 - 2:1, most preferably about 1:1.

Optionally, the carbon filler and the graphene particles have different sizes i.e. the size distribution of the carbon filler and the graphene particles is multimodal (has multiple peaks), for example, bimodal Wthout being bound by any theory it is believed that having two or more different sizes of conductive carbon particles leads to better conductivity as the small particles are able to fill in the holes in the matrix formed by the larger particles.

Polymer matrix material

Suitably, the polymer matrix material used in the present invention is an elastic material. The specific choice of elastic material is not particularly limited, provided that it is sufficiently elastically deformable at normal operating conditions and holds the graphene particles in position (so that the distribution of graphene particles does not change over time). Suitable materials include, for example, vinyl polymers (including polymers or copolymers of vinyl chloride, vinyl acetate and vinyl alcohol), polyester polymers, phenoxy polymers, epoxy polymers, acrylic polymers, polyamide polymers, polypropylenes, polyethylenes, silicones, elastomers such as natural and synthetic rubbers including styrene-butadiene copolymer, polychloroprene (neoprene), nitrile rubber, butyl rubber, polysulfide rubber, cis-1,4-polyisoprene, ethylene-propylene terpolymers (EPDM rubber), and polyurethane (polyurethane rubber). The polymer matrix material may be, for example, a copolymer of vinyl chloride, vinyl acetate and/or vinyl alcohol.

The polymer matrix material may be a thermoplastic material. Alternatively, the polymer matrix material may be a thermosetting material.

The polymer matrix material may comprise or be polyurethane, for example a thermoplastic polyurethane elastomer. Advantageously, the present inventors have found that using polyurethane (especially thermoplastic polyurethane elastomer) as the polymer matrix material produces good mechanical properties, in particular a good level of flexibility or stretchability, as well as good adhesion properties. This helps the heatable section to conform to the body of the wearer during use.

Heat Shield

In preferred embodiments of the invention, the heatable maternity bra comprises a layer located between the outermost section of the cup and the fabric with the heatable section. Advantageously, such layer can help to prevent heat generated by the heatable layer from escaping away from the wearer’s body. That is, the heatable maternity bra comprises a heat shield configured to direct heat generated by the heatable section towards the wearer’s body and in particular towards the breast. In this way, the heatable maternity bra is particularly efficient and the benefits of the present invention can be maximised. Thus, the heat shield comprises or consists of a thermally insulating material.

In such instances, the fabric with the heatable section is indirectly adhered to the bra body. The aforementioned fabric is adhered to the heat shield which is itself attached by convenient means to the bra body. Advantageously, the heat shield may provide a uniform surface for adherence (attachment) of the aforementioned fabric to other portions of the cup and/or to the bra body. In addition, the heat shield can reduce the mechanical stresses as the maternity bra is deformed, especially for materials having fibres that can move relative to one another.

The heat shield may be coated (for example, printed) on the maternity bra directly. For example, the maternity bra may have a heat shield coated on a cup comprising the fabric with the heatable section, with the graphene-containing fabric attached directly on the heat shield. Alternatively, the heat shield may be a pre-formed sheet of material which is adhered to the cup, for example, through the application of heat (e.g. from an iron).

The heat shield may be electrically insulating. Preferably, the heat shield is formed from an elastic material, e.g. an elastic polymer. Suitable materials include those mentioned above for the covering layer. For example, the intermediate layer may be, or comprise, silicone rubber, since this can provide excellent flexibility and deformability without cracking. A further preferred material for the heat shield is polyurethane, for example a thermoplastic polyurethane elastomer. Advantageously, incorporating a heat shield formed from polyurethane (especially thermoplastic polyurethane elastomer) may lead to heatable maternity bras with good mechanical properties, in particular a good level of flexibility. This helps the heatable maternity bra to conform to the body of the wearer during use.

In embodiments comprising both an electrically insulating covering layer and a heat shield, both of said layers may be made of the same material, e.g. silicone rubber or, preferably, polyurethane. In instances where both layers are formed from polyurethane (e.g. thermoplastic polyurethane), the heatable maternity bra can have particularly good mechanical properties (in particular, flexibility and conformability).

In embodiments comprising both an electrically insulating covering layer and a heat shield, the electrically insulating covering layer may encapsulate the heatable section. In such situations, the electrically insulating covering layer may form a waterproof seal. Typically, it is preferred that the heat shield not encapsulate the heatable section entirely, as a useful advantage of a heat shield is to help prevent escape of heat in one direction while not preventing escape of heat in another direction.

Innermost Layer

The innermost layer as used herein is a layer of the cup(s) comprising a heatable section, the innermost layer being that which is intended to contact the skin of the breast of the user.

The innermost layer is configured to sit next to the skin, is for heat dissipation, and generally includes a heat conductive, washable fabric. Generally, natural fabrics such as cotton and silk are preferred as they are comfortable next to the skin and allow the body to breath, as well as being able to absorb any milk which might leak into the bra.

In typical embodiments, the fabric comprising the heatable section corresponds with the innermost layer. This allows maximum benefit of heat transfer to the breast of the subject.

In other embodiments, an additional layer of material or fabric may lie between the fabric comprising the heatable section and the skin of the breast of the subject and forms the innermost layer. In such cases, the innermost layer is preferably made of a material which is not particularly thermally insulating, such as a thermally conductive material, to allow the heat generated by the heatable section to pass to the skin of the breast of the subject. In some such embodiments, the innermost layer may be made of a material that allows dissipation of the heat so that the heat is applied to a wider area of the breast than precisely that covered by an overlying heatable section. In some embodiments, the choice of material for the innermost layer is governed by comfort to the user. Suitable examples include cotton.

Particularly preferably, the innermost layer is cotton fabric and has a heatable section including graphene ink screen printed thereon.

Covering layer

Preferably, the heatable maternity bra comprises an electrically insulating covering layer, overlaying and directly or indirectly bonded to the fabric that has the graphene particles dispersed in a polymer matrix material. Advantageously, the electrically insulating covering layer helps to improve the mechanical properties of the heatable maternity bra. In particular, it reduces the occurrence of cracking upon deformation of the heatable maternity bra. Furthermore, the electrically insulating covering layer helps to electrically insulate the user from the heatable section and to prevent short-circuits forming when different regions of the heatable section are brought into contact (which might otherwise lead to non-uniform heating). In addition, the electrically insulating covering layer can protect the heatable section of the maternity bra from damage, e.g. by water during a wash process, and can allow higher temperatures to be achieved.

The electrically insulating covering layer may be adhered to the fabric that has graphene particles dispersed in a polymer matrix material. Most preferably, the electrically insulating covering layer is coated (e.g. printed) on the fabric.

Preferably, the electrically insulating covering layer is formed from an elastic material, e.g. an elastic polymer. This allows the covering layer to mechanically adapt as the wearer moves, increasing comfort for the wearer.

Suitable materials include, for example, vinyl polymers (including polymers or copolymers of vinyl chloride, vinyl acetate and vinyl alcohol), polyester polymers, phenoxy polymers, epoxy polymers, acrylic polymers, polyamide polymers, polypropylenes, polyethylenes, silicones, elastomers such as natural and synthetic rubbers including styrene-butadiene copolymer, polychloroprene (neoprene), nitrile rubber, butyl rubber, polysulfide rubber, cis-1,4-polyisoprene, ethylene-propylene terpolymers (EPDM rubber), and polyurethane (polyurethane rubber). The polymer matrix material may be, for example, a copolymer of vinyl chloride, vinyl acetate and/or vinyl alcohol.

Preferably, the electrically insulating covering layer is formed from a coatable material, such as a polymer ink. For example, the layer may be formed by polymer ink comprising a suspension of polymer particles in a liquid plasticizer (for example “Plastisol®” - a suspension of PVC particles in a liquid plasticizer), which can be printed and cured, for example, by heating. The electrically insulating covering layer may comprise or be formed from polyurethane, for example a thermoplastic polyurethane elastomer. Advantageously, the present inventors have found that using polyurethane (especially thermoplastic polyurethane elastomer) as the electrically insulating covering layer produces a heatable maternity bra with good mechanical properties, in particular a good level of flexibility. This helps the heatable maternity bra to conform to the body of the wearer during use.

The electrically insulating covering layer may be, or comprise, silicone rubber, since this can provide excellent flexibility and deformability without cracking.

Alternatively, or in addition, the heatable maternity bra may include an electrically insulating covering layer bonded to the bra body underneath the heatable section (e.g. as an innermost layer). For example, the heatable maternity bra may have electrically insulating covering layers bonded to both sides of the fabric with the heatable section, such that the heatable section is sandwiched between electrically insulating layers. In such embodiments, the covering layers may form a watertight seal.

Outermost Laver

The outermost layer as used herein is a layer of the cup(s) comprising a heatable section, the outermost layer being that which is intended to be furthest from the skin of the breast of the user and may be considered opposite to the innermost layer described above.

In some embodiments, the fabric comprising the heatable section corresponds with the outermost layer. Typically, however, it is expected that one or more additional layers will overlie the heatable section (i.e. that the fabric comprising the heatable section may not be the outermost layer).

In preferred embodiments, at least one layer of material or fabric overlies the fabric comprising the heatable section and the furthest from the innermost layer forms the outermost layer.

In some embodiments, the outermost layer may comprise or be the heat shield. In some embodiments, the outermost layer may comprise or be the covering layer. In some embodiments, the outermost layer is a further layer different from the fabric comprising the heatable section, the heat shield and the covering layer. In some embodiments, the outermost layer improves aesthetics or comfort and provides structural stability. Preferably the outer layer is polyester, cotton or silk.

CUPS

The cups of the heatable maternity bra typically comprise one or more than one of the layers discussed above, with at least one layer comprising the fabric having the heatable section.

Other layers may also be present. For brevity, we refer to “cup” in the following, but corresponding remarks apply to any cup or insert having a heatable section according to the invention. Similarly, “layer” can encompass more than one. Preferably, the cup comprises an innermost layer which comprises or is the fabric having the heatable section.

Preferably, the cup comprises an outermost layer which is not the fabric having the heatable section.

Preferably the fabric is obtained by screen printing an ink comprising the graphene particles dispersed in a matrix material onto a layer of fabric as described above. Preferably, the fabric is a cotton fabric, as this fabric is known to be suitable for screen printing. The region may extend over the whole cup or less than the whole, i.e. over only a part of the cup.

In some preferred embodiments, the cup comprises a heat shield between the fabric comprising the heatable section and the outermost layer.

Preferably, the heatable maternity bra is a multilayer bra having the following features: an innermost material for placement against the breast and for heat dissipation; a fabric comprising surface-functionalised graphene particles dispersed in a matrix material; an electronic system for controlling heating; and a battery or power supply system.

In the above, the innermost material may or may not comprise the fabric comprising surface- functionalised graphene particles dispersed in a matrix material.

The electronic system and battery or power supply is further discussed below.

The heatable maternity bra may also comprise additional layers such as those described above, as desired, so long as they do not affect the operation of the heatable section, such as a further decorative outermost layer.

Preferably, the heatable maternity bra body is fitted with flaps to allow the bra cups to be opened at the nipple to allow for breast feeding. Alternatively or additionally, the heatable maternity bra is openable to allow feeding at a portion connecting the cups or via a strap. Such opening options are known in the art.

Power Supply

The heatable maternity bra may include electrical connectors on (e.g. abutting/overlaying) the heatable section to facilitate connection of an electrical power supply. For example, the heatable maternity bra may include one or more metal (e.g. silver) regions to facilitate supply of electricity. Advantageously, these electrical connectors can simplify supply of power to the heatable section and can reduce its resistance. The one or more electrical connectors may take the form of points, or lines/tracks, optionally formed into a pattern. For example, the electrical connectors may take the form of spaced lines.

In some embodiments the one or more electrical connectors may be arranged to maintain electrical contact when the bra is undipped. Advantageously, this embodiment allows a user to turn on the heatable section if for example they want to p re- heat the bra before application of to the breast. In other embodiments, the one or more electrical connectors may be arranged so that electrical contact is prevented when the bra is undipped. Advantageously, this prevents the heatable section from operating when the bra is undipped and thus avoids battery wastage if for example the user forgets to turn off the heatable section once the benefits of the bra have been realised.

The heatable maternity bra of the present invention is connectable to an electrical power supply. The heatable maternity bra may include the electrical power supply, or it may be supplied without the eledrical power supply installed.

The electrical power supply may be a battery (for example, a button cell battery), or a supercapacitor. Alternatively, power may be supplied to the heatable maternity bra through an adaptor, such as a USB adaptor.

In embodiments comprising an electrically insulating covering layer, said layer may cover the power supply. In embodiments in which the fabric comprising the heatable section is encapsulated by eledrically insulating covering layers and/or an intermediate layer, said layers may also encapsulate the power supply. In such situations, the eledrically insulating covering layers and/or intermediate layer may form a waterproof seal around the heatable section and power supply. In such embodiments, the power supply may be rechargeable via electrical induction.

The heatable maternity bra may comprise a temperature control system, to control the temperature. For example, the control system may allow the amount of power supplied to be adjusted, e.g. in a stepped or continuous manner. This may control switching on and off, and/or switching between lower and high-power settings.

The control system may include an interface (such as a button, switch, or dial) for a user to adjust the temperature. In addition, or alternatively, the control system may be programmable to adjust the power level according to a pre-determined program. In this way, heating provided by the heatable maternity bra can be customised to a particular individual.

Preferably, the control system is configured so that the temperature cannot exceed a certain threshold (as per the temperature ranges mentioned above). Furthermore, the control system may include a cut-off feature, which reduces or stops power supply when a certain temperature is reached. The control system may be configured to control the temperature of the heatable section by voltage regulation, a positive temperature coefficient (PTC) thermistor, or by varying the duty cycle of the power supply.

The electronic system for controlling operation is typically expected to employ direct current (DC) operating at 5- 12V. Of course, a power supply having alternating current (AC) together with an AC-DV transformer may alternatively be suitable.

Hardware/Software

The heatable maternity bra may further comprise software and/or hardware configured to run by an external application (“app”).

“Software” means a set of instructions that when installed on a computer configures that computer with the readiness to perform one or more functions. The terms “computer program,” “application” and “app” are synonymous with the term software herein.

In some embodiments, one of more of the electronic features, settings or characteristics of the heatable maternity bra, such as temperature or battery level, can be viewed, selected, and/or adjusted remotely by a mobile electronic device, such as by way of a wireless communication protocol and/or using a software module or app on a mobile electronic device.

In particular, the software or app may allow a user to monitor the temperature of the heatable section(s) and to adjust the temperature in the range between 30 to 50 °C. The app may also allow the user to adjust the period over which the heatable maternity bra is heated from between 5 to 60 minutes (i.e. the app may act as a timer automatically switching off the heating after a set period of time).

In certain embodiments the heatable maternity bra comprises a controller chip and a temperature sensor configured to measure the temperature of the heatable section(s) and to adjust their temperature. The controller chip may be configured to receive commands from a mobile device. These commands may be transmitted using WiFi or Bluetooth communication.

In particularly advantageous embodiments, the heatable maternity bra is configured to align with a feeding schedule. In some embodiments, the heatable maternity bra is configured to allow a subject to input details of a feeding schedule into the app. In some embodiments, the heatable maternity bra is trainable to synchronise with (e.g. precede by a pre-set number of minutes) a feeding schedule. In these embodiments, the heatable maternity bra may be configured to turn on, achieve a desired temperature, and turn off after a defined period, according to the details of the feeding schedule. Accordingly, also provided herein are provides methods and uses of the heatable maternity bra according to the present invention as part of a feeding schedule. In such methods and uses, the feeding schedule may be input by the user into an app or be learned by bra software. Bra Inserts

In a separate further aspect, the present invention relates to heatable maternity bra inserts, which can be placed inside or onto a maternity bra for heating purposes.

The bra inserts comprise a fabric having one or more heatable sections as described above and are configured to fit into a maternity bra. For example, the bra inserts have a suitable shape and dimension for a maternity bra. The insert may comprise one or more additional layers and/or heat shield as set out herein for the maternity bra, in addition to the fabric comprising the heatable section. The insert may be configured to fit into a pouch arranged in or on a maternity bra, or any other suitable means. Where the bra insert is intended to fit into a pouch in a cup section of a maternity bra, it may not necessarily include other innermost or outermost layers.

A bra insert as defined herein advantageously allows a user to exchange an older insert for a new insert, or to remove the heatable section for washing for example. In addition, a maternity bra having the capability to have one or more (usually two) bra inserts has the advantage that the user can choose whether to wear the bra with or without the heating capability.

The present invention thus also relates to a heatable maternity bra comprising at least one - usually two - heatable bra inserts as described herein.

Uses and Methods of Use

The inventors have surprisingly found that a heatable maternity bra according to the present invention can increase milk production by more than 50% compared to milk production in the absence of heating.

Accordingly, in a still further aspect, the present invention relates to the use of a heatable maternity bra in a method of stimulating breast milk production in a postpartum subject.

In a still further aspect, the present invention relates to the use of a heatable maternity bra in a method of treating lactation insufficiency in a postpartum subject.

The present invention also relates to a method of treatment and the heatable maternity bra described above for use in a method of treatment.

In a certain aspect, the heatable maternity bra is used for treating lactation insufficiency in a postpartum subject.

Lactation insufficiency may arise from or be exacerbated by certain medical conditions. Examples of those medical conditions include but are not limited to polycystic ovary syndrome, hypothyroidism, hypoprolactinemia, theca lutein cysts, and hypertension. Subjects suffering from such medical conditions may therefore benefit particularly from the methods and uses of the invention. Accordingly, in certain embodiments, the postpartum subject is suffering from one of more of the following conditions polycystic ovary syndrome, hypothyroidism, hypoprolactinemia, theca lutein cysts, and hypertension.

Lactation insufficiency may also arise from or be exacerbated by prior surgical intervention in the breast area. Subjects for whom this is applicable may therefore benefit particularly from the methods and uses of the invention. Accordingly, in certain embodiments, the postpartum subject may have had breast surgery prior to breast feeding. Such surgery may be, for example, breast reduction, breast augmentation or removal of tissue (e.g. lumpectomy).

First- time mothers are statistically more likely to suffer from lactation insufficiency than mothers who have previously given birth. First-time mothers may therefore benefit particularly from the methods and uses of the invention. Accordingly, in certain embodiments, the postpartum subject may be a first-time mother. The number of children birthed in the most recent or previous instance(s) of childbirth is not particularly limited.

In preferred embodiments, milk supply is increased by more than 40%, more than 50%, more preferably by more than 60% and most preferably by more than 65% following the use of the heatable maternity bra or bra insert as described herein according to the methods and uses described herein, compared to not using (i.e. before use of) the maternity bra or insert.

In the uses and methods provided herein, the temperature of heating of the subject’s breast typically takes into consideration the following exemplary and non-limiting factors. The heatable maternity bra is preferably heatable to body temperature, or just above body temperature. The lower limit is therefore determined typically by the normal temperature of the breast, as in general some breasts will be cooler than others according to natural variation and environment. In general, the methods and uses herein employ a temperature higher than the normal temperature of the breast in order to achieve benefits such as improving milk production and soothing nipples. Accordingly, appropriate lower temperature is expected to be from 30°C, from 33 °C, from 35°C, or from 37°C. An expected suitable lower limit is 35°C. The upper limit must be a safe temperature i.e. a temperature which does not cause burning. Generally, it is preferred that the upper limit is also comfortable for the user and this may depend on factors such as the woman, the environment and the time of use. Accordingly, appropriate upper temperature is expected to be up to 70 °C, up to 50°C, up to 47°C, up to 45°C or up to 40°C. The above values may be combined to form suitable ranges. The appropriate temperature range could be determined by a medical professional, the user, or a combination thereof, such as for example 30 to 70°C. Preferably, the temperature of heating of the subject’s breast is expected to be from 35 to 45°C, or from 35 to 40°C. Without wanting to be bound by any theory it is believed that temperatures from 37 to 40 °C are suitable as they avoid burning of the skin but the inventors have found that they are still effective at soothing nipple pain and aiding milk production.

In the uses and methods provided herein, the time of heating of the subject’s breast typically takes into consideration the following exemplary and non-limiting factors. The feeding schedule of the child(ren) being nursed, the convenience of the subject, the extent of any lactation insufficiency, temperature and frequency of use might all impact the time of heating. In general, it is expected that a subject will be applying heat to the breast using the heatable maternity bra or insert according to the present invention for a time period of at least 5 minutes, at least 10 minutes or at least 15 minutes per use. As to an upper limit, it is expected that a subject will not usually heat the breast for longer than 30 minutes, such as up to 20 minutes or up to 15 minutes. The above values may be combined to form suitable ranges. The appropriate time could be determined by a medical professional, the user, or a combination thereof. Preferably, the time of heating the breast is between 5 to 20 minutes. More preferably, the method involves heating for a period of from 8 to 12 minutes per application to the breast. Without wanting to be bound by any theory this is believed to be the optimum time period for increasing milk production without causing damage to the milk due to heating of the milk.

In the uses and methods provided herein, the frequency of use of the heatable maternity bra or insert is expected to be primarily guided by the feeding schedule of the child(ren) being nursed although other factors, such as convenience of the subject, extent of any lactation insufficiency etc. might also be considerations. Typically, and without wishing to be bound by theory, the inventors believe that regular use of the heatable maternity bra or insert according to the invention will provide maximum benefit. For example, it is expected that the maternity bra or insert of the invention will be used in the methods and uses herein at least daily, probably more than once daily. In some embodiments, the frequency of use is at least twice daily, more preferably three or four times daily. If the child(ren) being nursed is (are) older, frequency of feeding may be less and therefore frequency of use of the heatable maternity bra or insert may be less, such as once daily. In some embodiments, such as those where the subject may use the bra to improve milk production for expressing e.g. using a breast pump, frequency of use may not follow a feeding schedule particularly closely.

In particularly preferred embodiments, the heatable maternity bra or insert according to the invention is used in the methods and uses herein at a temperature of between 35 to 45 °C for about 8-12 minutes per use.

Further preferably, the heatable maternity bra achieves its target temperature - such has the preferred temperatures described above - at a suitably convenient rate such as between 1 and 10 °C/min, preferably between 1 and 7 °C/min.

It should be noted that the above values for heating temperature, time and frequency also apply to the bra inserts provided herein.

In general, it should be noted that preferences described herein for uses apply appropriately to the corresponding methods also. Production Methods

In a further aspect, the present invention provides a method of manufacture of a heatable maternity bra according to the present invention, comprising

(a) providing a sheet of frabric; and

(b) depositing one or more layers of graphene particles dispersed in a polymer matrix material onto at least a portion of the fabric.

Step (b) may involve any suitable deposition technique, including, for example, bar coating, screen printing (including rotary screen printing), flexography, rotogravure, inkjet, pad printing, and offset lithography, whereby the conductive ink comprises the graphene particles dispersed in a solvent and polymer material. Preferably, the deposition technique used is screen printing. In such instances, it is further preferable that the method further comprises a step (c) of preparing an ink, the ink comprising surface treated graphene powder in an amount of 1- 10wt.%; carbon powder in an amount of 1-10wt.%; and a matrix material in an amount of 60-80 wt.%.

When using a conductive ink, the method preferably involves a step of preparing the ink for printing. This preparation step may involve mixing or homogenising the ink to evenly distribute the graphene particles in the ink’s polymer binder. Preferably, the preparation step involves homogenising the ink, since the inventors have found that this ensures a uniform distribution of carbon nanoparticles and can help to break up agglomerates of nanoparticles in the ink. Suitable homogenisation can be achieved using, for example, a three roll-mill or rotor-stator homogeniser.

The ink in step (c) may comprise:

1-50wt.% surface-treated graphene;

0-50wt.% carbon filler; and 50-90wt.% matrix material (binder).

In preferred embodiments, the ink in step (c) may comprise:

1-10wt.% surface-treated graphene;

1-10wt.% carbon filler; and 60-80wt.% matrix material (binder).

In some embodiments, the carbon filler is a carbon powder, and/or is functionalised.

The method of manufacture may further involve

(d) screen printing the ink on to the fabric to obtain a fabric having a conductivity of from 2 to 40 ohms, and a thickness of from 88 to 110 microns;

(e) attaching the fabric to the bra; and

(f) providing an electronic circuit. The electronic circuit is provided so that a user can, preferably conveniently and in some cases discreetly, cause heating of the heatable section.

When multiple layers comprising graphene particles are printed, each layer is preferably dried before a subsequent layer is added. The fabric may be heated after the application of each layer comprising graphene particles to speed up the drying process.

In certain embodiments, the layers of the bra body may be attached together by stitching or sewing the layers together.

It is noted that the preferences discussed above for the graphene, polymer matrix, fabric, electronics etc. apply equally to this section.

EXAMPLES

The present proposals are now explained further with reference to the accompanying figures in which:

Fig. 1 : a schematic diagram of a heatable maternity bra according to the present invention.

Fig. 2: a cross-sectional schematic diagram of a cup of a heatable maternity bra according to the present invention.

Fig. 3: results of a test used to determine the amount of milk produced with and without the use of a heatable maternity bra according to the present invention.

Figure 1 shows a schematic diagram of a heatable maternity bra according to the present invention, showing an outermost fabric 1, heat shield 2 and an innermost layer of fabric 3. A battery 4 is mounted on the straps of the bra.

The heatable maternity bra of this embodiment has a bra body connecting two cups. The bra body includes a section that extends from the front to the back of the wearer in use, as well as a portion below the cups, a portion above the cups, a portion between the cups and two straps.

In use, the straps of this embodiment extend over the shoulder of the wearer from a position above the breasts to the back. Other configurations of strap can be envisaged, such as a halterneck style, though from the perspective of supporting the breasts of a nursing mother the embodied configuration is preferred.

As shown in Figure 1 , a battery 4 is mounted on each strap of the bra. Each battery may power the heatable section(s) of one cup, though other configurations can be envisaged such as a single battery 4 on one strap or on a portion of the bra body above or below the cups. The electrical connectors are not shown.

In the embodiment of Figure 1, the heatable maternity bra is openable at the cup portion.

Means are shown between each cup and corresponding strap that enable opening of the cup by the user. Examples of such means include but are not limited to hooks or catches as are known in the art.

Figure 1 shows heat shield 2 located across three sections of the cup. These correspond to the locations of heatable sections, which lie underneath. One heat shield is located toward the upper part of the cup, near an opening means. Two further heatable sections 2 are located further down the cup. In use, these locations might correspond to the lower part of the breast under and partially around the nipple. Thus, it can be seen that the heat shield and heatable sections do not extend across the whole of the cup in this embodiment. Of course, in other embodiments the heat shield 2 may extend across the whole of the cup. In still other embodiments, the heat shield 2 may not extend across the whole of the cup but there may be one, two, four, or other number of heat shield 2 portions. Additionally, the shape of the heat shield 2 portions is not limited to that shown as other shapes might advantageously be used.

An intermediate layer may include an electronic system.

In the embodiment of Figure 1 innermost layer 3 comprises the graphene-containing fabric. The innermost layer in some embodiments comprises cotton fabric. In other embodiments, the innermost layer may be coated to allow dissipation of the heat generated by the heatable section.

As shown in the figures, the innermost layer extends across the whole of the cup. The outermost layer 3 extends over the heat shield 2 and across the whole of the cup.

Figure 2 shows a schematic cross-sectional diagram of a cup of a heatable maternity bra according to the present invention. The innermost layer 3 is fabric and contacts the skin of the breast when in use. The heat shield 2 extends over the innermost layer and an outermost layer 1 of fabric extends over the heat shield 2. Each layer has a curved cross-sectional shape in the usual way of a bra cup. The size and relative size may be varied according to e.g. the breast size.

It should be noted that the schematic cross-sectional diagram of Figure 2 could alternatively represent a bra insert according to the present invention.

EXPERIMENTAL EXAMPLES Example 1

In a first set of experiments the thermal ink print area required for various breast sizes was investigated.

A conductive graphene ink was prepared comprising:

1.0 wt.%-10.0 wt.% surface-treated graphene powder;

1.0 wt.%-10.0 wt.% carbon powder; and 60 wt.% - 80 wt.% binder. The ink was screen printed onto the fabric of the bra. The results are shown in Table 1.

Table 1 : the ink print area and the thermal ink thickness of the heatable pad for various bra cup sizes

Example 2

In a second set of experiments, the effect of washing on the resistance of the thermal inks was assessed using an example screen printed bra from those prepared above. Washing was carried out at room temperature for 15 minutes.

The resistance values were as follows:

Table 2: resistance of thermal pads after washing

Example 3

In example 3 the effect of the amount of power supplied on the current was evaluated. The results are shown in table 3. A multimeter was used to measure the resistance of samples of fabric with graphene particles dispersed in a polymer matrix printed thereon. Next, the samples were washed at room temperature for 15 minutes before drying in an incubator. The resistance was measured after washing. The same was done for other washing times. Table 3: the temperature obtained for a particular power supplied

Example 4

Example 4 demonstrates the increase in milk production for a subject using the heatable maternity bra according to the present invention.

A female subject at 2-3 months postpartum initially expressed milk using a Philips AVENT model CLASSIC TWIN ELECTRONIC PUMP SCF 303/01. During the first two weeks of the trial the subject was given a controlled diet.

Test protocol

For the first week of the trial the subject followed the following protocol. The heatable maternity bra was not used during this week period and the subject’s breasts were not warmed. Table 5: Details of the schedule for expressing milk during week 1

Following the first week of testing the subject used a heatable maternity bra according to the present invention for 10 minutes at 40 °C prior to expressing breast milk. The results of this study are given in the table below.

Table 6: Details of the schedule for expressing milk during week 2 of the trail, heatable maternity bra was used for 10 minutes prior to milk being expressed.

During the final week of the trial the subject was not subjected to a controlled diet. The times at which milk was expressed and the duration of use of the heatable maternity bra during the third week is given in the table below.

Table 8: Details of the schedule for expressing milk during week 3 of the trail, heatable maternity bra was used for 10 minutes prior to milk being expressed and the subject was not on a controlled diet.

Figure 3 shows the results of the study. The x axis shows milk volume (oz.) and the y axis represents the day of the week (day 1 , day 2 etc., up to day 7). From left to right, the bars of each set of three shows the results of (i) week 1 , no use of a maternity bra according to the invention and with food control; (ii) week 2, use of a maternity bra according to the invention and with food control; and (iii) week 3, use of a maternity bra according to the invention and without food control. The use referred to is as set out herein.

As can be seen from Figure 3, the milk volume data from week 1 is roughly 4.5 oz, consistently on each day. The milk volume data from week 2 is substantially higher, at or close to 7 oz each day. Similar results to week 2 are observed at week 3.

When the subject used the heatable maternity bra, milk product was increased by up to 68 % compared to not using the maternity bra (regardless of whether food and beverage intake was controlled). This data supports that the heatable maternity bra is effective in increasing milk production.

Example 5

The influence of using the heatable bra for a set period of time on volume of milk expressed and on the feeling of the breasts was also tested. The results of these tests are shown in the table below.

Table 9: Effects of using the heatable maternity bra to heat to 40 °C on the milk quantity and the side effects this produces

These results demonstrate that heating for 10 minutes leads to increased milk production without causing heat pain or burning of the skin. Therefore, this is a suitable time period for heating in order to increase milk production, but also to ease pain.

Claims

1. A heatable maternity bra comprising a bra body connecting two cups, wherein at least one cup includes a fabric with a heatable section comprising graphene particles dispersed in a polymer matrix material.

2. A heatable maternity bra according to claim 1 , wherein the graphene particles are surface-functionalised graphene particles.

3. A heatable maternity bra according to claim 1 or 2, wherein the heatable section has a sheet resistance of from 3 to 40 W/square, or from 4 to 30 W/square, or from 5 to 20 W/square, or from 7 to 17 W/square.

4. A heatable maternity bra according to claim 2 or 3 wherein the surface-functionalised graphene particles are oxygen-functionalised, hydroxy-functionalised, carboxy-functionalised, carbonyl-functionalised, amine-functionalised, amide-functionalised and/or halogen- functionalised, preferably wherein the surface-functionalised graphene particles are amine- functionalised, amide-functionalised or halogen functionalized graphene.

5. A heatable maternity bra according to any one of the preceding claims, wherein the surface-functionalised graphene particles have hydroxyl, carbonyl, carboxyl, amine, amide or a mixture of these functionalities present on the particles’ surface.

6. A heatable maternity bra according to any one of the preceding claims, wherein the heatable section has a thickness of from 50 to 150 pm, preferably from 88 to 110 pm.

7. A heatable maternity bra according to any one of the preceding claims, further comprising a heat shield located between the heatable section and an outermost layer.

8. A heatable maternity bra according to any one of the preceding claims, wherein the bra further comprises software and/or hardware such that the bra is configured to be linked to a mobile phone application for measuring and/or controlling temperature and/or for monitoring battery life.

9. A heatable maternity bra according to claim 8, wherein the bra is configured to follow a feeding schedule.

10. A heatable maternity bra according to any one of the preceding claims, wherein the heatable section comprises 1-10wt.% surface functionalised graphene powder.

11. A heatable maternity bra according to any one of the preceding claims, wherein the graphene particles dispersed in a polymer matrix material form part of a printable ink.

12. A heatable maternity bra according to any one of the preceding claims, wherein the heatable section comprises:

1-10wt.% surface functionalise graphene powder;

1-10wt.% carbon powder; and 60-80wt.% matrix material.

13. A heatable maternity bra according to any one of the preceding claims, wherein the at least one cup comprises a first layer of internal coating fabric for heat dissipation; a second layer comprising the fabric with a heatable section; and an outer layer.

14. A heatable maternity bra according to any one of the preceding claims, comprising an innermost material for placement against the breast and for heat dissipation; a fabric comprising surface-functionalised graphene particles dispersed in a matrix material; an electronic system for controlling heating; and a battery or power supply system.

15. A heatable maternity bra insert for inserting into a cup of a heatable maternity bra, the insert comprising a fabric with a heatable section comprising graphene particles dispersed in a polymer matrix material.

16. A heatable maternity bra, optionally according to any one of claims 1 to 14, comprising at least one bra insert according to claim 15.

17. Use of a heatable maternity bra according to any one of claims 1-14 or 16, or of an insert according to claim 15, in a method of stimulating breast milk production in a postpartum subject.

18. Use of a heatable maternity bra according to any one of claims 1-14 or 16, or of an insert according to claim 15, in a method of treating lactation insufficiency in a postpartum subject.

19. Use according to claim 17 or 18, wherein the postpartum subject is a first-time mother.

20. Use according to any one of claims 17-19, wherein the subject is suffering from one or more of the following conditions: polycystic ovary syndrome, hypothyroidism, hypoprolactinemia, theca lutein cysts, and hypertension; or wherein the subject has had prior breast surgery.

21. A method of stimulating breast milk production in a postpartum subject, the method comprising applying a heatable bra according to any one of claims 1-14 or 16, or an insert according to claim 15, to at least one breast.

22. A method of treating lactation insufficiency in a postpartum subject, the method comprising applying a heatable bra according to any one of claims 1-14 or 16, or an insert according to claim 15, to at least one breast.

23. A method of treating lactation insufficiency or of stimulating breast milk production in a postpartum subject, the method comprising heating a subject’s breast to a temperatue of from 35 to 45 °C using a heatable maternity bra according to any one of claims 1-14 or 16, or using an insert according to claim 15, for a time of 5 to 60 minutes.

24. A method according to any one of claims 21 to 23, comprising heating to a temperature of from 37 °C to 40 °C.

25. A method according to any one of claims 21 to 24, wherein the heating is carried out for a period of from 8 to 12 minutes.

26. Use of a heatable maternity bra according to any one of claims 1-14 or 16, or of an insert according to claim 15, in a method according to any one of claims 21 to 25.

27. A method of manufacture of a heatable maternity bra according to any one of claims 1- 14 or 16, or an insert according to claim 15, comprising:

(a) providing a sheet of frabric; and

28. A method of manufacture according to claim 27, wherein the depositing in step (b) includes screen printing.

29. A method according to claim 28, comprising:

(c) preparing an ink, the ink comprising surface treated graphene powder in an amount of 1-50wt.%; carbon filler in an amount of 0-50wt.%; and a matrix material in an amount of 50-90wt.%

30. A method according to claim 29, wherein the method comprises:

(d) screen printing the ink on to the fabric to obtain a heatable section having a conductivity of from 2 to 40 ohms, and a thickness of from 88 to 110 microns;

(e) attaching the fabric to the bra; and

(f) providing an electronic circuit to allow heating of the heatable section.