GB2602155A

GB2602155A - Textile-based sensing device

Info

Publication number: GB2602155A
Application number: GB2020273.5A
Authority: GB
Inventors: Dean Scott; Castle Christopher; Orts Mercadillo Vicente; Steiner Pietro; Blu Steiner Carlo
Original assignee: Graphene Trace Ltd
Current assignee: Graphene Trace Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2022-06-22
Also published as: GB202020273D0

Abstract

There is provided a textile-based sensing device for sensing an object’s position and/or movement, the device comprising: a textile article; a plurality of conductive ink-based electrodes (38,40) formed on and/or embedded in at least one textile surface of the textile article to define first and second sets of electrodes, the first set of electrodes (38) electrically insulated from the second set of electrodes (40), the first set of electrodes spatially intersecting with the second set of electrodes to define a plurality of intersection nodes (42, figure 2), each intersection node defining a respective one of a plurality of capacitive sensors, wherein each capacitive sensor is configured to, in use, provide an output electrical signal responsive to sensing a presence of the object in a vicinity of the capacitive sensor and/or responsive to sensing an application of pressure by the object.

Description

Intellectual Property Office Application No G132020273.5 RTM Date:21 April 2021 The following terms are registered trade marks and should be read as such wherever they occur in this document: Wi-H Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

TEXTILE-BASED SENSING DEVICE

The invention relates to a textile-based sensing device for sensing an object's position and/or movement.

It is known to incorporate sensors into textile objects for sensing a range of parameters.

According to a first aspect of the invention, there is provided a textile-based sensing device for sensing an object's position and/or movement, the textile-based sensing device comprising: a textile article; a plurality of conductive ink-based electrodes formed on and/or embedded in at least one textile surface of the textile article to define first and second sets of electrodes, the first set of electrodes electrically insulated from the second set of electrodes, the first set of electrodes spatially intersecting with the second set of electrodes to define a plurality of intersection nodes, each intersection node defining a respective one of a plurality of capacitive sensors, wherein each capacitive sensor is configured to, in use, provide an output electrical signal responsive to sensing a presence of the object in a vicinity of the capacitive sensor and/or responsive to sensing an application of pressure by the object.

The mutually electrically insulated configuration of the electrodes on or in the textile article results in a textile-based sensing device with a capacitive sensing array having a proximity sensing capability and/or a pressure sensing capability. An object approaching or touching a given capacitive sensor will alter a local electric flux between the corresponding mutually insulated electrodes, thus producing a measurable change in electric flux. An object applying pressure to the textile article will cause deformation of the textile article that alters a local electric flux around the or each capacitive sensor affected by the applied pressure, thus producing a measurable change in electric flux. An object applying pressure to a given capacitive sensor will compress the corresponding mutually insulated electrodes towards each other at the intersection node and thereby cause a measurable change in electric field strength at the intersection node. An object touching the textile article will couple to an electric flux around the or each capacitive sensor close to the contact point between the object and the textile article, thus producing a measurable change in electric flux.

Using conductive ink to fabricate the capacitive sensors on or in the textile article enables incorporation of the capacitive sensors into the textile article in a minimally obtrusive manner that retains aesthetic and/or tactile qualities of the textile article and provide comfortable support to a user contacting the textile article, without compromising on the sensing capabilities of the capacitive sensors. Incorporation of the capacitive sensors into a wide range of textile articles is made possible by the scalability and adaptability of the conductive ink-based electrode manufacturing process to textile articles and materials of different types, shapes and sizes. In addition, the conductive ink-based electrode manufacturing process can be applied to finished textile articles, thus obviating the need for significant redesign and modification of the original textile article manufacturing process.

The spatially intersecting and mutually electrically insulated arrangement of the first and second sets of electrodes results in an arrangement of individually addressable capacitive sensors that requires fewer electrical connections and contacts than a conventional arrangement of individual distinct sensors, each having its own electrical connections and contacts. For example, for an array with M columns and N rows of sensors, the minimum number of electrical connections required for the invention would be (M+N) while the minimum number of electrical connections required for the conventional sensor arrangement would be (MxN). The invention therefore permits a higher density of capacitive sensors, if desired, to provide increased sensing resolution but also broadens the range of available designs for the arrangement of the individually addressable capacitive sensors.

Also, the spatially intersecting and mutually electrically insulated arrangement of the first and second sets of electrodes not only enables the fabrication of the functional sensors and its electrical connections in a single manufacturing step, or a minimal number of manufacturing steps, but also provides the invention with greater design and manufacturing freedom that is compatible with a conductive ink-based electrode manufacturing process. More specifically, varying levels of complexity of the layout, shape and dimensions of the capacitive sensors of the invention can be readily fabricated using the conductive ink-based manufacturing process to suit a particular textile article or sensing application. In contrast, an increased complexity of the conventional arrangement of individual distinct sensors would require a more complicated manufacturing process, such as multiple deposition and coating steps, which not only increases manufacturing cost and lead time but also may not be suitable for certain textile articles, especially more delicate textile articles.

The invention may be used in medical applications. The invention may be used to identify and treat medical conditions that include, but are not limited to, immobility, bad postures, sleeping position and gait. The invention may be used in non-medical applications. The invention may be used for information gathering and data collection, such as collecting data on movement of objects on a surface or contact with an object's surface for one-way or two-way interfaces between objects. The invention is applicable to wearable technology, disability support and sleep and movement disorder diagnostics and therapeutics. The invention may be used for identifying and tracking general sleeping behavior, posture control, pressure sore prevention, baby monitoring, body image reconstruction, sports performance analysis (such as running power measurements) and medical diagnosis.

The invention may be used as a textile-based artificial skin for a human body part, a robotic part or a prosthetic.

It will be appreciated that the list of applications of the invention in this specification. are not intended to be limiting.

The use and configuration of the textile-based sensing device and its components may vary, non-limiting examples of which are set out as follows.

The object may be an inanimate object or a part thereof, a person or a part thereof, or an animal or a part thereof.

The textile article may be manufactured using any textile manufacturing process, such as weaving, knitting, crocheting, felting and so on. The textile article may include synthetic fibres and/or natural fibres. For the purposes of this specification, the term "textile" is intended to encompass the terms "fabric" and "cloth".

The first and second sets of electrodes may be arranged to provide regular or periodic spacing between the intersection nodes. Alternatively the first and second sets of electrodes may be arranged to provide irregular spacing between the intersection nodes.

The first and second sets of electrodes may be arranged so that the intersection nodes are aligned to form straight rows and straight columns of the intersection nodes. Alternatively the first and second sets of electrodes may be arranged so that the intersection nodes are out of alignment.

The intersection nodes is preferably arranged as a square or rectangular grid of intersection nodes but may be arranged to form differently shaped arrays of intersection nodes, such as a radial array, a circumferential array, a spiral array, a helical array and a complex polygonal array.

The shape and dimensions of each electrode may vary depending on various requirements, such as sensing requirements and manufacturing capability. For example, the shape of each electrode may be designed to tailor a sensitivity of each capacitive sensor.

In embodiments of the invention, each electrode may include a plurality of primary electrode sections and a plurality of secondary electrode sections arranged so that each primary electrode section is located intermediate of a pair of the secondary electrode sections. Each primary electrode section may spatially correspond to a respective one of the intersection nodes. Each primary electrode section may be narrower in width than the neighbouring pair of secondary electrode sections.

Configuring the electrodes in this manner increases the sensing capability of each capacitive sensor and permits optimisation of the sensitivity of each capacitive sensor through selection of suitable shapes and sizes of the primary and secondary electrode sections. For example, each pair of secondary electrode sections may be tapered in a direction towards the intermediate primary electrode section. In non-limiting examples, each tapered secondary electrode section may be shaped as a triangle, a diamond, a rhombus or a trapezium. The tapered shape of each secondary electrode sections permits design of a more compact and sensitive configuration of the corresponding capacitive sensor.

In a preferred embodiment of the invention, each electrode includes alternating primary and secondary electrode sections. Other arrangements of the primary and secondary electrode sections in each electrode is possible as long as each primary electrode section is located intermediate of a pair of the secondary electrode sections.

The primary electrode sections and/or the secondary electrode sections may include complex outlines including, but not limited to, cutouts and protrusions in the plane of the electrode sections. The first and second sets of electrodes may include respective geometrically complementary cutouts and protrusions. This is to increase the electrode perimeter length of the first and second sets of electrodes around a given intersection node. Complementary cutouts on one set of electrodes may be the negative of the protrusions on the other set of electrodes.

In further embodiments of the invention, each electrode may include an electrode line portion. The inclusion of the electrode line portion in each electrode is particularly suitable for achieving the spatially intersecting arrangement of the first and second sets of electrodes. In particular, the electrode line portions of the first set of electrodes may be arranged to be perpendicular to the electrode line portions of the second set of electrodes. This makes it more straightforward to design and manufacture the capacitive sensing array. It is envisaged that, in other embodiments of the invention, the electrode line portions of the first set of electrodes may be arranged to be at any angle between 00 and 900 to the electrode line portions of the second set of electrodes. It is also envisaged that, in still other embodiments of the invention, each electrode line portion may be straight, curved or a combination thereof.

The first and second sets of electrodes may be formed on and/or embedded in respective opposite textile surfaces of the same textile layer. Alternatively the first and second sets of electrodes may be formed on and/or embedded in respective textile surfaces belonging to different textile layers of the textile article.

The textile article may include at least one textile layer separating the first and second sets of electrodes. That is to say, a single textile layer or multiple textile layers may be arranged between the first and second sets of electrodes.

The textile article may include at least one insulating layer separating the first and second sets of electrodes. That is to say, a single insulating layer or multiple insulating layers may be arranged between the first and second sets of electrodes. The insulating layer, or at least one of the insulating layers, may be a textile layer or a non-textile layer. The insulating layer, or at least one of the insulating layers, may be a dielectric layer. The insulating layer, or at least one of the insulating layers, may be formed of a printable material, for example a polymer-based material, a two-dimensional material, an emulsion or resin. The printable material may be, but is not limited to, a screen-printable material.

The electrodes may be covered by one or more textile layers and/or one or more insulating layers, and/or may be covered by a protective coating or film.

S

Different types of conductive ink may be used to make the electrodes. Each electrode may be made of a single type of conductive ink, or may be made of a combination or mixture of multiple types of conductive inks. Different parts of the same electrode may be made of the same conductive ink or different types of conductive inks. For example, the electrode line portion may be made of a different conductive ink than that of the secondary electrode portion(s).

The plurality of conductive ink-based electrodes, or at least one of the conductive ink-based electrodes, may be made of metallic ink, such as silver or copper ink.

The plurality of conductive ink-based electrodes, or at least one of the conductive ink-based electrodes, may be made of carbon-based ink. The carbon ink may comprise graphite, graphene or carbon nanotubes.

Graphene is a two-dimensional material of sp2-bonded carbon atoms arranged in a hexagonal lattice. Graphene includes monolayer graphene, bilayer graphene, trilayer graphene and few-layered graphene (10 layers of graphene). In the embodiment of the invention made of graphene-based carbon ink, the graphene-based carbon ink may include, but is not limited to, graphene flakes, graphene platelets, graphene ribbons and/or graphene sheets. The graphene-based ink may include pristine graphene, chemically functionalised graphene and/or graphene derivatives.

In embodiments of the invention, the plurality of conductive ink-based electrodes may be infused into at least one textile surface of the textile article. In particular, the plurality of conductive ink-based electrodes may be infused into yarns or fibres of the textile article. This provides a reliable way of incorporating the capacitive sensors into the textile article in a minimally obtrusive manner. Preferably the plurality of conductive ink-based electrodes are flush, or substantially flush, with the at least one textile surface on which they are formed and/or in which they are embedded.

The textile-based sensing device may include one or more other electrical or electronic component (such as an antenna) formed on and/or embedded in at least one textile surface of the textile article. The or each other electrical or electronic component may be made of conductive ink. The or each other electrical or electronic component may be printable on the textile article.

In a preferred embodiment of the invention, the textile-based sensing device is for sensing an object's position and/or movement when the object is in contact with a soft furnishing or wearable article. Examples of soft furnishings include, but are not limited to, furniture, beds, sofas, armchairs, wheelchairs, vehicle seats, mattresses, upholstery, mattress covers, cushion covers, seat covers, carpets, mats and exercise pads. Examples of wearable articles include, but are not limited to, garments, armbands, wristbands, body pads and insoles for footwear.

The capacitive sensing array of the invention enables measurement of a broad range of proximity-related parameters and/or a broad range of pressure-related parameters using minimally obtrusive conductive ink-based capacitive sensors that do not interfere with the primary function of the textile article. In a first example, the invention may be used to monitor and track a person's usage of a textile article to assess whether the person is using the textile article properly or whether the person's usage of the textile article has changed over time. Such usage may include, but is not limited to, lying down on the textile article, sitting down on the textile article, standing on the textile article, using the textile article while moving (e.g. walking, running or jogging) and wearing the textile article.

There are different ways of using each capacitive sensor to, in use, provide an output electrical signal responsive to sensing a presence of the object in a vicinity of the capacitive sensor and/or responsive to sensing an application of pressure by the object.

For example, in embodiments of the invention, the textile-based sensing device may include a controller configured to sequentially apply a driving voltage to the first set of electrodes, wherein the controller may be further configured to read the resultant output electrical signals from the second set of electrodes. This provides a reliable way of configuring the capacitive sensors to be individually addressable. Such a controller may include a microcontroller.

In further embodiments of the invention, the textile-based sensing device may include a controller configured to process the output electrical signals from the capacitive sensors to generate data corresponding to the sensed presence of the object and/or the sensed pressure applied by the object. The controller may be configured to obtain the output electrical signals from the capacitive sensors via direct electrical contact with the electrodes, wired connections and/or wireless connections (e.g. as near-field communication (NFC), BluetoothTM, Wi-H).

The data may include the output electrical signals themselves and/or information derived from the output electrical signals. The data may include temporal data, spatial data or a combination thereof.

The data may include data about the object's pressure distribution on the textile article. Such data may include, but is not limited to, a pressure map, gradient information and coefficient of variation information. The pressure map may include information about the object's position and/or weight distribution on the textile article. The mutually insulating arrangement of the first and second sets of electrodes results in a capacitive sensing array that is particularly conducive to collection of pressure distribution data.

The data may include physiological information. For example, the data includes one or more breathing characteristics and/or cardiac information such as heart rate. The minimally obtrusive configuration of the conductive ink-based electrodes ensures that the use of the textile-based sensing device is comfortable for a user or a patient.

In embodiments of the invention, the controller may include a processor and memory including computer program code, the memory and computer program code configured to, with the processor, enable the controller at least to analyse the output electrical signals so as to generate the data.

The data may be used to provide feedback to a user using the textile object, or an observer (e.g. a medical practitioner or a carer) overseeing the user using the textile object. The feedback may be provided in real-time or may be recorded and provided at a later time. The feedback may be provided automatically or may be manually controlled by the user or the observer viewing the data. The feedback may be, but is not limited to, visual feedback, aural feedback, haptic feedback, heat feedback, cooling feedback or a combination thereof.

In embodiments of the invention, the textile-based sensing device may include at least one haptic actuator, wherein the controller may be configured to selectively operate the or each haptic actuator responsive to the data so as to provide haptic feedback. The haptic feedback may be provided to the object or a different object. The invention may be used to provide targeted haptic feedback to the object or a different object to, for example, provide treatment or relief. The haptic feedback may be used to prompt a person to change their position while lying or sitting down on the textile article. The haptic feedback may be used to increase or diminish pressure applied to certain parts of the user's body. The haptic feedback may be used to stimulate circulation of blood flow.

The haptic feedback is provided by different types of haptic actuators, non-limiting examples of which are described as follows.

The or each haptic actuator may be configured to be flush, or substantially flush, with a textile surface of the textile article in an unactuated mode.

The haptic actuator, or at least one of the haptic actuators, may include a movable actuator member operable to selectively provide the haptic feedback as an out-ofplane mechanical protrusion or depression.

The haptic actuator, or at least one of the haptic actuators, may include a shape memory actuator member operable to change its shape to provide the haptic feedback. When the haptic feedback is no longer required, the or each shape memory actuator is capable of automatically returning to its original shape. The or each shape memory actuator member may be made of, for example, shape memory alloy.

The haptic actuator, or at least one of the haptic actuators, may include a motor operable to drive the haptic feedback.

The haptic actuator, or at least one of the haptic actuators, may include a bimetallic strip.

Optionally the or each haptic actuator may be integrally formed with the textile article. Alternatively the or each haptic actuator may be separately formed from the textile article. For example, the or each haptic actuator may form part of an object that is physically separate from the textile article. Further alternatively one or more haptic actuators may be integrally formed with the textile article, and one or more other haptic actuators may be separately formed from the textile article.

In further embodiments of the invention, the textile-based sensing device may include at least one temperature control element. The controller may be configured to selectively control the or each temperature control element responsive to the data to provide a change in temperature. The or each temperature control element may be a heater for providing heat, or may be a cooler for providing cooling. The heat/cooling may be provided to the object or a different object. The invention may be used to provide targeted heating/cooling to the object or a different object to, for example, provide treatment, relief, air flow around the object or other forms of heating/cooling effects useful for textile articles and their use.

Optionally the or each temperature control element may be integrally formed with the textile article. Alternatively the or each temperature control element may be separately formed from the textile article. For example, the or each temperature control element may form part of an object that is physically separate from the textile article. Further alternatively one or more temperature control elements may be integrally formed with the textile article, and one or more other temperature control elements may be separately formed from the textile article.

The or each temperature control element may be a Peltier device (e.g. a Peltier heater or a Peltier cooler). The or each temperature control element may be in the form of one or more pipes (e.g. heating pipes or cooling pipes).

The or each temperature control element may be made of conductive ink. Hence, the or each temperature control element may be manufactured using the conductive ink-based electrode manufacturing process.

In embodiments of the invention, the or each temperature control element may be formed in the textile layer, or one of the textile layers, incorporating the plurality of electrodes. In other embodiments of the invention, the or each temperature control element may be formed on or in a textile layer separate from the or each textile layer incorporating the plurality of electrodes. The or each temperature control element may be positioned at, over or adjacent an intersection node, or a respective intersection node.

According to a second aspect of the invention, there is provided a method of manufacturing a textile-based sensing device according to any one of the first aspect of the invention and its embodiments, the method comprising the steps of: providing the textile article; manufacturing the plurality of conductive ink-based electrodes to be formed on and/or embedded in the at least one textile surface of the textile article to define the first and second sets of electrodes.

The features and advantages of the textile-based sensing device of the first aspect of the invention and its embodiments apply mutatis mutandis to the features and advantages of the method of the second aspect of the invention and its embodiments.

In a preferred embodiment of the invention, the method may include the step of printing the conductive ink-based electrodes onto the at least one textile surface of the textile article to define the first and second sets of electrodes. Preferably the method includes the step of screen-printing the conductive ink-based electrodes onto the at least one textile surface of the textile article to define the first and second sets of electrodes. The printing step may be used to manufacture other components of the invention that are made of conductive ink, such as the or each insulating layer, an antenna, and other electrical or electronic components.

It will be appreciated that the use of the terms "first" and "second" and the terms "primary" and "secondary", and the like, in this patent specification is merely intended to help distinguish between similar features, and is not intended to indicate the relative importance of one feature over another feature, unless otherwise specified.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, and the claims and/or the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and all features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which: Figure 1 shows a mattress cover according to a first embodiment of the invention; Figure 2 shows components of the mattress cover of Figure 1; Figures 3 and 4 show an exemplary layout of a capacitive sensing array of the mattress cover of Figure 1; Figure 5 shows an alternative exemplary layout of a capacitive sensing array of the mattress cover of Figure 1; Figures 6 to 10 show an individual capacitive sensor; Figure 11 illustrates an exemplary application of the mattress cover of Figure 1; Figures 12 and 13 shows an exemplary haptic actuator of the mattress cover of Figure 1; Figure 14 shows an exemplary heater array of the mattress cover of Figure 1; Figures 15a and 15b shows a wheelchair according to a second embodiment of the invention; and Figures 16, 17a, 17b and 17c show examples of haptic actuators.

The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic form in the interests of clarity and conciseness.

The following embodiments of the invention are described with reference to the use of the invention with certain soft furnishings and wearable articles. It will be appreciated that the description of the following embodiments of the invention apply mutatis mutandis to the use of the invention with other soft furnishings, other soft furnishing covers, other wearable articles and other types of textile articles.

A textile-based sensing device according to a first embodiment of the invention is shown in Figures 1 and 2 and is designated generally by the reference numeral 30.

The textile-based sensing device 30 comprises a textile article and a capacitive sensing array.

The textile article 30 is a multi-layer mattress cover 30. The mattress cover 30 includes first, second and third inner textile layers 32a,32b,32c. The mattress cover 30 further includes outer textile layers 34a,34b. The textile layers 32a,32b,32c,34a,34b are made of cotton but in other embodiments may be made of other textile materials. Typically the mattress cover 30 is arranged over a mattress 36 and underneath a bed sheet (not shown).

A first set of electrodes 38 is embedded in a textile surface of the third inner textile layer 32c. The second inner textile layer 32b is sandwiched between the first and third inner textile layers 32a,32c. A second set of electrodes 40 is embedded in a textile surface of the first inner textile layer 32a. The inner textile layers 32a,32b,32c are sandwiched between the outer textile layers 34a,34b. The construction of the textile layers 32a,32b,32c,34a,34b and the sets of electrodes 38,40 results in a mutually electrically insulated arrangement of the first and second sets of electrodes 38,40 within the mattress cover 30.

In other embodiments of the invention, the second inner textile layer 32b may be replaced by a dielectric layer. In still other embodiments of the invention, the first and second sets of electrodes 38,40 may be embedded in respective opposite textile surfaces of the same textile layer.

The electrodes 38,40 are manufactured using a screen-printing process that infuses conductive ink into the fibres of the textile layers 32a,32c, so that the conductive ink-based electrodes are flush, or substantially flush, with the textile surfaces in which they are embedded. The plurality of conductive ink-based electrodes 38,40 are made of carbon-based ink, preferably graphene-based ink.

Figure 3 shows a layout of the first and second sets of electrodes 38,40. The first set of electrodes 38 comprises M number of electrodes that respectively include straight electrode line traces that are arranged in parallel and spaced apart from each other. The second set of electrodes 40 comprises N number of electrodes that respectively include straight electrode line traces that are arranged in parallel and spaced apart from each other. The electrode line traces of the first set of electrodes 38 are perpendicular to the electrode line traces of the second set of electrodes 40 so that the spatial intersection of the electrode line traces defines a square array of intersection nodes 42 arranged in straight rows and straight columns, with regular spacing between the intersection nodes 42. M and N are each six in the embodiment shown but may have different values in other embodiments.

Each electrode 38,40 further includes a series of alternating primary and secondary electrode sections 44,46 along a length of its electrode line trace. Each intersection node 42 is formed by an overlap of a respective primary electrode section 44 of the first set of electrodes 38 with a respective primary electrode section 44 of the second set of electrodes 40, with a portion of the second inner textile layer 32b sandwiched between the primary electrode sections 44, as shown in Figure 4. Each primary electrode section 44 is located intermediate of a pair of the secondary electrode sections 46, except for the primary electrode sections 44 at the proximal ends of the electrode lines traces. Each pair of secondary electrode sections 46 is tapered in a direction towards the intermediate primary electrode section 44. Each tapered secondary electrode section 46 in this embodiment is shaped as a diamond that overlays the electrode line trace but in other embodiments may have a different shape, such as a triangle, a rhombus or a trapezium. For example, as shown in Figure 5, the tapered secondary electrode sections 46 at the end of each electrode line trace are shaped as triangles that overlay the electrode line trace.

The textile-based sensing device 30 includes a controller 48 that comprises a microcontroller and processor.

The first set of electrodes 38 are designated as respective drive lines 38. The second set of electrodes 40 are designated as respective sense lines 40. The drive lines 38 are connected to respective outputs of the controller 48. In use, the microcontroller sequentially applies a driving voltage to the drive lines 38 one at a time. The driving voltage applied to a given drive line 38 is turned off before a driving voltage is applied to the next drive line 38. The driving voltage may be a fixed DC voltage or a modulated DC voltage. The sense lines 40 are connected to respective inputs of the controller 48 and connected to ground using pull-down resistors 50. The controller 48 measures voltages across the pull-down resistors 50 simultaneously. The drive and sense lines 38,40 may be respectively connected to output and inputs of the controller 48 using wired connections, or conductive ink-based electrical connections or a combination of wired connections and conductive ink-based electrical connections.

As shown in Figure 6, each intersection node 42 in combination with the surrounding secondary electrode sections 46 defines a respective capacitive sensor 52 that forms a sensing pixel 52 of the capacitive sensing array. Thus, the plurality of capacitive sensors 52 form a plurality of pixels 52 of the capacitive sensing array.

The geometry and dimensions of each pixel 52 may be varied to tailor the functional performance of the corresponding capacitive sensor 52, such as the resolution and sensitivity of the corresponding capacitive sensor 52. Examples of such variables Li, L2, L3 and L4 are shown in Figure 7. Li is the width of the primary electrode section 44, L2 is the width of the gap between adjacent secondary electrode sections 46 of intersecting and mutually electrically insulated electrodes 38,40, L3 is the width of the secondary electrode section 46, and L4 is the length of the primary electrode section 44 that is also the separation between successive secondary electrode sections 46 of the same electrode 38,40. The values of Li, L2, L3 and L4 may vary depending on sensing requirements (e.g. resolution, sensitivity) and manufacturing limitations (e.g. screen-printing limitations, textile limitations).

Optionally the first and second sets of electrodes 38,40 may include respective geometrically complementary cutouts and protrusions. This is to increase the electrode perimeter length of the first and second sets of electrodes 38,40 around a given intersection node 42. Figure 8 shows an embodiment in which complementary cutouts 45 on one set of electrodes may be the negative of the protrusions 47 on the other set of electrodes.

Figure 9 shows a state of a single pixel 52 within the capacitive sensing array at quiescence, i.e. when the capacitive sensor 52 is inactive. The curved lines represent electric field lines 54 between the mutually insulated electrodes 38,40 when a driving voltage is applied to the drive line 38. As seen in Figure 9, the electric field lines 54 extend between the overlapping primary electrode sections 44 and between adjacent secondary electrode sections 46.

Figure 10 shows changes in the state of a single pixel 52 within the capacitive sensing array when the capacitive sensor 52 is active. An object 56 approaching or touching a given pixel 52 will alter a local electric flux between the drive and sense lines 38,40, thus producing a measurable change in electric flux. An object 56 applying pressure to the textile article 30 will cause deformation of the textile layers 32a,32b,32c that alters a local electric flux around the or each pixel 52 affected by the applied pressure, thus producing a measurable change in electric flux. An object 56b touching the textile article 30 will couple to an electric flux around the or each capacitive sensor 52 close to the contact point between the object 56b and the textile article 30, thus producing a measurable change in electric flux. An object 56 applying pressure P to a given capacitive sensor 52 will compress the corresponding drive and sense lines 38,40 towards each other at the intersection node 42 and thereby cause a measurable change in electric field strength at the intersection node 42 in comparison to the uncompressed drive and sense lines 38,40. The change in electric field strength increases with the amount of pressure applied to the capacitive sensor 52. These electrical changes are read as output voltage signals by the controller 48 through simultaneous measurement of the voltages across the pull-down resistors 50.

In this way, each capacitive sensor 52 is configured to, in use, provide an output voltage signal responsive to sensing a presence of the object in a vicinity of the capacitive sensor 52 and/or responsive to sensing an application of pressure by the object.

The processor is configured to process the output voltage signals from the capacitive sensors 52 to generate data corresponding to the sensed presence of the object and/or the sensed pressure applied by the object. The processor may be configured to have multiplexing capability, or may be configured to work with a separate processor or device with multiplexing capability. The controller 48 includes a processor and memory including computer program code, the memory and computer program code configured to, with the processor, enable the controller 48 at least to analyse the output voltage signals so as to generate the data. In other embodiments of the invention, the controller 48 may be, may include, may form part of or may be associated with one or more of an electronic device, a portable electronic device, a portable telecommunications device, a mobile phone, a personal digital assistant, a tablet, a phablet, a desktop computer, a laptop computer, a server, a cloud computing network, a smartphone, a smartwatch, smart eyewear, and a module for one or more of the same. It will be appreciated that references to a memory or a processor may encompass a plurality of memories or processors. The controller 48 may be part of the mattress cover or separate from the mattress cover.

The configuration of the invention of Figure 1 results in a smart mattress cover 30 for sensing a person's position and movement when the person is on the mattress 36 overlaid by the mattress cover 30. More specifically, the smart mattress cover 30 may be used to monitor and track the person's usage of the mattress 36 to assess whether the person is using the mattress 36 properly or whether the person's sleeping pattern has changed over time.

When a person is lying on the mattress cover 30, their body will contact, or be in proximity with, multiple pixels 52 of the capacitive sensing array. The design of the capacitive sensing array enables measurement of the body's position and weight distribution on the mattress in the form of a matrix of voltage values, which correspond to the positions of the pixels 52 in the capacitive sensing array. Continuous measurement of the output voltage signals adds temporal information about the body's position and weight distribution on the mattress 36, which permits real-time monitoring of the body's movement to track sleeping patterns over time.

The data may include a pressure map in the form of a contour plot that recreates the body's position and weight distribution on the mattress 36. Optionally the pressure map may include data points interpolated using smoothing algorithms.

The pressure map may be displayed on a display screen 58 in real-time, as shown in Figure 11, or may be saved for viewing at a later time. The contour plot of the pressure distribution may be projected onto the display screen 58 for visual feedback to encourage adherence to a specific sleeping regime or a specific treatment. Optionally the display screen may show an animated avatar 60 reproducing the user's position and movement in real-time or in a "time-lapse" style video for later viewing. The display screen 58 may be, or may form part of, a display monitor, a mobile device, electronic device, a portable electronic device, a portable telecommunications device, a mobile phone, a personal digital assistant, a tablet, a phablet, a computer, a desktop computer, a laptop computer, a smartphone, a smartwatch, smart eyewear, and a module for one or more of the same.

The data may be automatically compiled into medical reports that are saved or sent to a medical personnel in a local or remote location. This allows the medical personnel to evaluate the data for diagnosis and treatment of a variety of ailments (e.g. bad backs, obstructive sleep apnoea and bed sores).

Features of the pressure map data may be used to track sleeping behaviour and identify sleeping poses (e.g. supine poses). For example, the pressure map data can be analysed to classify the user's body position based on the position of key pressure points (e.g. shoulders, hips, posterior, knees, ankles), which are used to track the user's posture and position. This in turn can be used to identify characteristic features of other sleep disorders, such as restless leg syndrome, sleepwalking and confusional arousal.

The information provided by the capacitive sensing array enables sleep scientists and clinicians to help diagnose and treat sleep disorders and empower sufferers of bad sleep to gain new, deeper insights into their sleep behaviour and seek any necessary medical attention. In an exemplary application, the invention may be used to help treat obstructive sleep apnoea (OSA) by monitoring a user' resting position and posture of a user and provide treatment to the user if the position or posture is unhealthy. There are many examples of unhealthy positions and postures leading to health problems. For instance, positional obstructive sleep apnoea (pOSA) is exacerbated by sleeping supine.

The data may include physiological information about the user, such as breathing characteristics and/or cardiac information such as heart rate. Ballistocardiography (BCG) measurements are possible by measuring changes in the pressure map due to the sudden injection of blood into great vessels with each heart-beat. These repetitive pulses have a general periodicity that can be extracted from the overall pressure map using, for example, signal filters and/or Fourier analysis. The physiological information may be used to help assess whether the user's sleeping position or posture is healthy and/or identify any sudden changes in the user's health.

The data obtained from the capacitive sensing array may be used to trigger haptic feedback and targeted heating to provide the user with treatment or relief. It will be understood that the haptic feedback and targeted heating features are not essential to the invention but are merely optional features.

Optionally the textile-based sensing device may include haptic actuators 62 to provide haptic feedback to the user to treat, or provide relief from, a variety of ailments. The haptic actuators 62 are operated by the controller 48 to provide the haptic feedback responsive to the data obtained from the capacitive sensing array.

Figure 12 shows an exemplary haptic actuator 62. Each haptic actuator 62 includes a shape memory alloy (SMA) actuator member 62 that is operable to change its shape to provide the haptic feedback. Each SMA actuator member 62 in the embodiment shown is in the form of a strip but in other embodiments may have a different design (e.g. a wire actuator 62a, a thinner or wider strip 62b, a leaf spring actuator 62c, an Q-shaped actuator 62d, a 7-shaped actuator, as shown in Figure 13). The SMA actuator members 52 are integrally formed with the mattress cover 30, e.g. sewn into a textile layer of the mattress cover 30. The SMA actuator members 62 may be connected directly to the controller 48 or may be connected wirelessly to the controller 48.

Each SMA actuator member 62 in its cooled state 64 lies flush, or substantially flush, with the textile surface of the textile layer in which it is incorporated. When heated above its transition temperature, each SMA actuator member 62 in its heated state 66 expands or contracts due to a change in lattice structure to form an out-of-plane bulge in the textile layer. The heating may be in the form of Joule heating through application of an electrical current through the SMA actuator member 62. The transition temperature of the SMA actuator members 62 may be selected to tune the triggering of the haptic feedback. When the haptic feedback is no longer required, cooling the SMA actuator member 62 enables it to return to its original shape.

The formation of the out-of-plane bulges provides haptic feedback to the user lying on the mattress cover 30. If a user's sleeping position or posture is detrimental to their well-being and health, the data is used to trigger haptic feedback to encourage healthy sleeping positions for the treatment of obstructive sleep apnoea. If a supine position is detected, the microcontroller triggers the SMA actuator members 62 to disturb the user in their sleep, increasing in intensity until the user turns over. Multiple SMA actuator members 62 may be coordinated to prompt the user to move their body in a specific direction. For example, as shown in Figure 12, the timing of the creation of the out-of-plane bulges by the array of SMA actuator members 62 may be coordinated to create a rolling wave effect 68 along the mattress 36 that disturbs the user until they move into a preferable position.

The strength and timing of the haptic feedback provided by the SMA actuator members 62 is adjusted to avoid causing pain to the sleeping user and to avoid waking up the sleeping user.

Once a healthy position or posture is detected, the haptic feedback will cease. The haptic feedback event may be recorded for future reference. The haptic feedback event may include, but is not limited to, time spent in an unhealthy position or posture, the strength of the haptic feedback required to move the user to the healthy position or posture, and the time required to move the user to the healthy position or posture. This may be included in medical reports that is sent to medical personnel and is made available to the user via a companion app or associated human interface device.

The haptic feedback may be configured to stimulate circulation of blood flow in the body of the user. In particularly the stimulation of circulation of blood flow may be responsive to physiological information derived from the pressure data obtained by the capacitive sensing array.

It is envisaged that, in other embodiments of the invention, at least one of the haptic actuators may form part of an object that is separate from the mattress cover. For example, at least one of the haptic actuators may form part of a pillow case or a wearable, such as a wearable strap. The or each such haptic actuator may be wirelessly connected to the controller.

It is also envisaged that, in still other embodiments of the invention, the or each SMA actuator may be replaced by a different type of haptic actuator. For example, another type of haptic actuator may be in the form of a vibration motor.

Each haptic actuator 62 may be replaced by a light source that provides visual feedback or by a sound source (e.g. a buzzer) that provides aural feedback.

Optionally the textile-based sensing device may include heaters 70 to provide targeted heating to the user to treat, or provide relief from, a variety of ailments such as muscle soreness or to control air flow around the user. The heaters 70 are operated by the controller 48 to provide the targeted heating.

Figure 14 shows a layout of a heater array. A first set of heater electrodes 72 comprises straight electrode line traces that are arranged in parallel and spaced apart from each other. A second set of heater electrodes 74 comprises straight electrode line traces that are arranged in parallel and spaced apart from each other. The electrode line traces of the first set of heater electrodes 72 are perpendicular to the electrode line traces of the second set of heater electrodes 74. Each heater 70 is in the form of a resistive coil that interconnects a heater electrode of the first set of heater electrodes 72 with a heater electrode of the second set of heater electrodes 74. The first set of electrodes 72 are connected to a power supply 76. The second set of electrodes 74 are connected to ground. In this way each heater is individually addressable.

The heater electrodes 72,74 and the heaters 70 are embedded in a textile surface of an additional textile layer. The additional textile layer is added to the mattress cover so that each heater 70 is arranged to overlap a respective pixel 52 of the capacitive sensing array. The heater electrodes 72,74 and the heaters 70 are preferably made of conductive ink so that the heater electrodes 72,74 and the heaters 70 may be manufactured using screen-printing.

It is envisaged that, in other embodiments of the invention, each heater may have a different shape, such as a meandering or serpentine shape.

It is also envisaged that, in still other embodiments of the invention, each heater may be integrally connected with either or both of the first and second sets of electrodes.

The targeted heating can be carried out in two ways.

Firstly, the heaters 70 may be operated by the controller 48 to automatically provide the targeted heating responsive to the data derived from the output voltage signals from the capacitive sensing array. In this way the textile-based sensing device 30 can sense the body's position on the mattress 36 and activate the heaters 70 corresponding to the body's position, thus delivering heat to the body. If the body moves, the textile-based sensing device can sense the body's movement and adjust the targeted heating by activating the heaters 70 corresponding to the body's new position and deactivating the other heaters 70. The textile-based sensing device 30 can also sense the position of a specific body part on the mattress 36 and activate the heaters 70 corresponding to the body part's position, thus delivering heat to the specific body part instead of the entire body.

Secondly, the user or an observer may manually select the area of the body to be heated via a user interface device. The user interface device may be integrated into the textile-based sensing device 30 or may be a separate device connected either wirelessly or using wired connections to the textile-based sensing device 30. The user interface device may include, but is not limited to, a companion app. Once the area of the body is selected, the textile-based sensing device 30 senses the position of the selected body area on the mattress 36 and activate the heaters 70 corresponding to the selected body area's position, thus delivering heat to the selected body area. If the body moves, the textile-based sensing device 30 can sense the selected body area's movement and adjust the targeted heating by activating the heaters 70 corresponding to the selected body area's new position and deactivating the other heaters 70. The user or observer may also choose the duration of the targeted heating (e.g. 15 minutes, 30 minutes, 1 hour, 2 hours, etc.).

As a result, the textile-based sensing device 30 is capable of adapting to a user's natural movements to deliver continuous targeted heating to the user's body, specific body part or selected body area.

The heating temperature of each heater 70 is adjusted to avoid causing pain to the sleeping user and to avoid waking up the sleeping user.

It is envisaged that, in other embodiments of the invention, at least one of the heaters may form part of an object that is separate from the mattress cover. For example, at least one of the heaters may form part of a pillow case or a wearable, such as a wearable strap. The or each such heater may be wirelessly connected to the controller.

It is further envisaged that, in still other embodiments of the invention, the textile-based sensing device may include coolers to provide targeted cooling to the user to treat, or provide relief from, a variety of ailments such as muscle soreness or to control air flow around the user. The coolers are operated by the controller 48 to provide the targeted cooling. Optionally the textile-based sensing device may include both heaters and coolers.

The non-invasive, real-time and full-body tracking characteristics of the invention, together with the optional haptic feedback and targeted heating, not only minimises inconvenience to the user and permits monitoring of the user under natural sleeping conditions, but also permits automatic monitoring and thereby obviating the need for an observer (e.g. medical personnel) to be constantly watching over the user. This opens up the possibility of diagnosis and treatment of sleep-related disorders, many of which have symptoms and characteristics related to nocturnal movements. Conventionally such sleep-related disorders are challenging to monitor and manage, least not due to the inconvenience of current technology for the management of pOSA that must be worn by the user and fully charged for proper operation.

A textile-based sensing device according to a second embodiment of the invention is shown in Figures 15a and 15b. The textile-based sensing device of the second embodiment of the invention is similar in structure and operation to the textile-based sensing device of the first embodiment of the invention shown in Figure 1.

The textile-based sensing device of the second embodiment of the invention differs from the textile-based sensing device of the first embodiment of the invention shown in Figure 1 in that the textile-based sensing device of the second embodiment of the invention is in the form of a seat cover 76 for a wheelchair 78, where the seat cover 76 comprises the capacitive sensing array embedded in one or more textile layers 80 of the seat cover 76. The seat cover 76 is placed over a cushion 82. Optionally the seat cover 76 may be overlaid by upholstery. Figure 15a shows the wheelchair 78, while Figure 15b shows an exploded view of the seat cover 76.

Many patients suffer immobility due to a temporary, chronic or long-term health condition and thereby rely on wheelchairs for transportation. Wheelchairs for such patients are sometimes made with bespoke cushioning that are tailored to fit the patient's contours to provide comfort and support them to sit upright. However, sitting in a fixed position for prolonged periods can lead to the development of pressure sores and ulcers at contact points between the patient and the wheelchair.

By integrating the seat cover 76 into the wheelchair 78 and having the patient sit normally in the wheelchair 78, the pressure sensing capability of the textile-based sensing device can then be used to identify pressure points on the patient that will eventually lead to pressure sores and ulcers. The minimally obtrusive configuration of the capacitive sensing array means that the patient does not experience any discomfort from sitting on the seat cover 76.

The data derived from the capacitive sensing array may include a pressure map that can be used by medical personnel to examine the patient's sitting position to identify pressure points and intervene before the onset of pressure sores, to fix the sitting posture of the patient and/or to redesign the wheelchair 78 to eliminate the pressure points that would lead to pressure sores and ulcers. The data obtained from the capacitive sensing array may be visualised as a contour plot or as an animated avatar. The data obtained from the capacitive sensing array may include information about the pressure distribution on the seat cover 76 over time.

Optionally the second embodiment of the invention may comprise the haptic feedback and/or targeted heater features described above with respect to the first embodiment of the invention.

It will be appreciated that the features of the second embodiment of the invention apply mutatis mutandis to other types of furniture for sitting, such as armchairs, office chairs, sofas, benches and so on. The invention finds particular application in the office where office workers can develop chronic back pain by sitting with poor postures for extended periods.

There is provided a textile-based sensing device according to a third embodiment of the invention. The textile-based sensing device of the third embodiment of the invention is similar in structure and operation to the textile-based sensing device of the first embodiment of the invention shown in Figure 1.

The textile-based sensing device of the third embodiment of the invention differs from the textile-based sensing device of the first embodiment of the invention shown in Figure 1 in that the textile-based sensing device of the third embodiment of the invention is in the form of an insole for footwear, where the insole comprises the capacitive sensing array embedded in one or more textile layers of the insole. It will be appreciated that, in some embodiments, the capacitive sensing array may be embedded in one or more textile layers that is then affixed to an existing insole.

When a user wearing the footwear moves (e.g. walks, runs or jogs), they will alternately lift and put down their footwear. This results in a change in pressure applied to the insole over time. The pressure data can be used to measure information about the user's movement, such as step count, cadence and power output (e.g. walking or running power). Furthermore, the textile-based sensing device can be used to sense the user's weight distribution on the insole, which provides further information about the user's movement, such as posture and gait.

The information about the user's movement can be monitored using a companion user interface device, such as an app on a smartwatch or smartphone application, which can store and display the information in a visually appealing and insightful manner. The controller 48 of the textile-based sending device may be configured to communicate with the user interface device via wireless connections (e.g. as near-field communication (NFC), BluetoothTM, Wi-Fi).

The minimally obtrusive configuration of the capacitive sensing array means that the user does not experience any discomfort from the insole when moving.

It will be appreciated that the insole can also be used to measure user performance while playing sports, such as football, basketball, tennis and so on.

The mutually electrically insulated configuration of the electrodes on or in the textile article results in a textile-based sensing device with a capacitive sensing array having a proximity sensing capability and/or a pressure sensing capability. The spatially intersecting and mutually electrically insulated arrangement of the first and second sets of electrodes results in an arrangement of individually addressable capacitive sensors 52 that requires fewer electrical connections and contacts than a conventional arrangement of individual distinct sensors, each having its own electrical connections and contacts.

A readily scalable screen-printing process is used to manufacture the conductive ink-based electrodes, which enables incorporation of the capacitive sensors 52 into various types of textile articles in a minimally obtrusive manner that retains aesthetic and/or tactile qualities of the textile article and provide comfortable support to a user contacting the textile article, without compromising on the sensing capabilities of the capacitive sensors 52. Furthermore, the use of screen-printing to manufacture the functional capacitive sensors 52 and its electrical connections from conductive ink not only minimises the number of manufacturing steps but also is compatible with a wide range of textile article manufacturing processes.

Figure 16 shows exemplary haptic actuators for use in embodiments of the invention. Each haptic actuator may be made of a shape memory material (such as shape memory alloy) and/or may be actuatable by heating. Figure 16a shows a beam-shaped haptic actuator 84, which may be physically constrained at one end or both ends. Figure 16b shows a beam-shaped haptic actuator 86 with a centrally located disc section 88, which is physically constrained at both ends. Figure 16c shows a haptic actuator 90 comprising three beams circumferentially spaced apart by 120° from each other, where each beam is joined to the other two beams at one of its ends and is physically constrained at its other end. Figure 16d shows a haptic actuator 92 comprising four beams circumferentially spaced apart by 90° from each other, where each beam is joined to the other three beams at one of its ends and is physically constrained at its other end, and where a disc section 94 is located at the joint between the four beams. Figure 16e shows a haptic actuator 96 comprising five beams circumferentially spaced apart by 72° from each other, where each beam is joined to the other four beams at one of its ends and is physically constrained at its other end. The number of beams may be more than five. The circumferential spacing between the beams in the same haptic actuator may have the same value or may have different values.

Figures 17a and 17b show an exemplary haptic actuator 98 for use in embodiments of the invention. A first cylinder 100 is coaxially placed inside a second, wider cylinder to define a two coaxial cylinder arrangement. The first cylinder 100 is slidable into and out of the second cylinder 102. The cylinders are preferably made of low friction material, such as polytetrafluoroethylene. A shape memory alloy spring 104 is housed between the two coaxial cylinders so that a first end of the shape memory alloy spring 104 contacts an inner end face of the first cylinder 100 and so that a second end of the shape memory alloy spring 104 contacts an inner end face of the second cylinder 102. In use, each cylinder is connected to a respective voltage potential so that the shape memory alloy spring 104 completes the electrical circuit to have a voltage applied thereacross. Heating and cooling of the shape memory alloy spring 104 enables movement 106 of the first cylinder 100 into and out of the second cylinder 102. Joule heating of the shape memory alloy spring 104 causes it to expand on reaching its transition temperature, thus pushing the first cylinder 100 outwards away from the second cylinder 102. Removing the voltage supply permits cooling of the shape memory alloy spring 104 so that it contracts and thereby permits the first cylinder 100 to slide back into the second cylinder 102. Optionally a biasing element 108, such as a spring, may be employed to help the shape memory alloy spring 104 return to its original position. The structure of the biasing element 108 as drawn in Figures 17a and 17b is merely exemplary and not intended to be limiting.

The haptic actuator arrangement may include an array of haptic actuators that are independently actuatable to apply various pressure patterns to a user's body. This may be to, for example, increase or diminish pressure applied to certain parts of the user's body and/or to stimulate circulation of blood flow. In a specific example, Figure 17c shows an array of haptic actuators 98, each of which is identical to the haptic actuator 98 of Figures 17a and 17b arranged inside a soft furnishing 110, such as a mattress, a seat or a cushion.

The listing or discussion of an apparently prior-published document or apparently prior-published information in this specification should not necessarily be taken as an acknowledgement that the document or information is part of the state of the art or is common general knowledge.

Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.

Claims

CLAIMS1. A textile-based sensing device for sensing an object's position and/or movement, the textile-based sensing device comprising: a textile article; a plurality of conductive ink-based electrodes formed on and/or embedded in at least one textile surface of the textile article to define first and second sets of electrodes, the first set of electrodes electrically insulated from the second set of electrodes, the first set of electrodes spatially intersecting with the second set of electrodes to define a plurality of intersection nodes, each intersection node defining a respective one of a plurality of capacitive sensors, wherein each capacitive sensor is configured to, in use, provide an output electrical signal responsive to sensing a presence of the object in a vicinity of the capacitive sensor and/or responsive to sensing an application of pressure by the object.
2. A textile-based sensing device according to Claim 1 wherein each electrode includes a plurality of primary electrode sections and a plurality of secondary electrode sections arranged so that each primary electrode section is located intermediate of a pair of the secondary electrode sections, wherein each primary electrode section spatially corresponds to a respective one of the intersection nodes, and wherein each primary electrode section is narrower in width than the neighbouring pair of secondary electrode sections.
3. A textile-based sensing device according to Claim 2 wherein each pair of secondary electrode sections is tapered in a direction towards the intermediate primary electrode section.
4. A textile-based sensing device according to Claim 2 or Claim 3 wherein the primary electrode sections and/or the secondary electrode sections include cutouts and protrusions in the plane of the electrode sections.
5. A textile-based sensing device according to Claim 4 wherein the first and second sets of electrodes include respective geometrically complementary cutouts and protrusions.
6. A textile-based sensing device according to any one of the preceding claims wherein each electrode includes an electrode line portion.
7. A textile-based sensing device according to Claim 6 wherein the electrode line portions of the first set of electrodes are arranged to be perpendicular to the electrode line portions of the second set of electrodes.
8. A textile-based sensing device according to any one of the preceding claims wherein the textile article includes at least one insulating layer separating the first and second sets of electrodes.
9. A textile-based sensing device according to Claim 8 wherein the insulating layer, or at least one of the insulating layers, is made of a printable material.
10. A textile-based sensing device according to any one of the preceding claims wherein the plurality of conductive ink-based electrodes are infused into the at least one textile surface of the textile article.
11. A textile-based sensing device according to any one of the preceding claims wherein the textile article is or forms part of a soft furnishing.
12. A textile-based sensing device according to Claim 11 wherein the textile article is a mattress cover, a cushion cover or a seat cover.
13. A textile-based sensing device according to any one of Claims 1 to 10 wherein the textile article is or forms part of a wearable article.
14. A textile-based sensing device according to Claim 13 wherein the textile article is an item of clothing, an undergarment, or an insole for footwear.
15. A textile-based sensing device according to any one of the preceding claims including a controller configured to sequentially apply a driving voltage to the first set of electrodes, wherein the controller is further configured to read the resultant output electrical signals from the second set of electrodes.
16. A textile-based sensing device according to any one of the preceding claims including a controller configured to process the output electrical signals from the capacitive sensors to generate data corresponding to the sensed presence of the object and/or the sensed pressure applied by the object.
17. A textile-based sensing device according to Claim 16 wherein the data includes data about the object's pressure distribution on the textile article.
18. A textile-based sensing device according to Claim 16 or Claim 17 wherein the data includes physiological information.
19. A textile-based sensing device according to Claim 18 wherein the data includes one or more breathing characteristics and/or cardiac information.
20. A textile-based sensing device according to any one of Claims 16 to 19 including at least one haptic actuator, wherein the controller is configured to selectively operate the or each haptic actuator responsive to the data so as to provide haptic feedback.
21. A textile-based sensing device according to Claim 20 wherein the or each haptic actuator includes a shape memory actuator member operable to change its shape to provide the haptic feedback.
22. A textile-based sensing device according to any one of Claims 16 to 21 including at least one temperature control element, wherein the controller is configured to selectively control the or each temperature control element responsive to the data to provide a change in temperature.
23. A textile-based sensing device according to Claim 22 wherein the or each temperature control element is made of conductive ink.
24. A method of manufacturing a textile-based sensing device according to any one of the preceding claims, the method comprising the steps of: providing the textile article; manufacturing the plurality of conductive ink-based electrodes to be formed on and/or embedded in the at least one textile surface of the textile article to define the first and second sets of electrodes.
25. A method according to Claim 24 including the step of printing the conductive ink-based electrodes onto the at least one textile surface of the textile article to define the first and second sets of electrodes.