CN117782202A - Distributed touch sensor based on flexible optical waveguide and sensing method - Google Patents
Distributed touch sensor based on flexible optical waveguide and sensing method Download PDFInfo
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Abstract
The invention provides a distributed touch sensor based on a flexible optical waveguide and a sensing method. The present application relates to the field of optics, and in particular to distributed tactile sensors for flexible optical waveguides. The distributed touch perception method based on the flexible optical waveguide comprises a reference optical waveguide inner core, a sensing optical waveguide inner core containing a dyeing wedge-shaped part and an optical waveguide cladding, and the simultaneous measurement of touch contact position and contact force is realized according to the optical loss of the reference optical waveguide and the optical loss of the optical waveguide containing the dyeing wedge-shaped part. The touch sensor is composed of a first optical waveguide inner core, a second optical waveguide inner core and a cladding layer, wherein the cladding layer wraps the first optical waveguide inner core and the second optical waveguide inner core, the first optical waveguide inner core and the second optical waveguide inner core are uniform in width and are arranged in parallel and in isolation, and at least one colored wedge-shaped part exists in the second optical waveguide inner core.
Description
Technical Field
The invention relates to the field of robot touch sensors and optics, in particular to a distributed touch sensor of a flexible optical waveguide.
Background
Stretchable flexible tactile sensors with multiple sensing modes can provide smart robots with sensing capabilities comparable to touch. The basic principles of flexible tactile sensors are generally divided into resistive, capacitive, piezoelectric and optical sensing. The optical-based flexible touch sensor has the remarkable advantages of high biocompatibility, no electromagnetic interference, chemical inertia, low output signal hysteresis, high precision and the like.
On the other hand, the basic characteristics of light, such as intensity, wavelength, polarization and propagation direction, can be used to detect disturbances in the sensing medium. Based on these characteristics, distributed fiber optic sensing has become a reliable option for monitoring mechanical deformations of rigid infrastructures such as bridges, roads, etc. Although distributed optical fiber sensing has the potential of performing multifunctional sensing in soft materials, the factors such as inextensibility of traditional silica optical fibers, huge volume of laser light sources, expensive detection equipment, tiny backscattering wavelength shift and the like prevent the traditional distributed optical fiber sensing from being applied to the research fields of soft robots, virtual reality, biomedicine and the like.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention provides the distributed touch sensor and the sensing method based on the flexible optical waveguide, and the sensor manufactured by the distributed touch sensing method based on the flexible optical waveguide has the capabilities of flexibility and simultaneously detecting the multi-point touch pressure and the touch position.
The technical scheme adopted by the invention is as follows:
the invention discloses a distributed touch sensor based on a flexible optical waveguide, which mainly comprises: a first optical waveguide core 1, a second optical waveguide core 6, and a cladding 7, the cladding 7 completely surrounding the first optical waveguide core 1 and the second optical waveguide core 6;
the first optical waveguide core 1 and the second optical waveguide core 6 are arranged in parallel and separated in the cladding 7; the input end of the first optical waveguide inner core 1 is connected with a first light source or an external optical fiber 14, and the output end of the first optical waveguide inner core 1 is connected with a photoelectric detector or an external optical fiber 15; the core widths of the first optical waveguide inner cores 1 are the same, namely the widths of the first optical waveguides 1 are uniform along a first direction, and the first direction is the direction in which the optical waveguide input end points to the optical waveguide output end;
the input end of the second optical waveguide inner core 6 is connected with a second light source or an external optical fiber 16, and the output end of the second optical waveguide inner core is connected with a second photoelectric detector or an external optical fiber 17; the second optical waveguide core 6 has a colored wedge-shaped portion therein, which has a varying core width along the first direction; at least two positions in the second optical waveguide core 6 are different in color, and at least two positions in the colored wedge-shaped part of the second optical waveguide core are different in core width;
the refractive index of the first optical waveguide core 1 and the second optical waveguide core 6 is greater than the refractive index of the outer layer of the cladding 7, so that frustrated total internal reflection is generated at the interface between the first optical waveguide core 1 and the second optical waveguide core 6 and the cladding 7.
Preferably, the longitudinal section of the colored wedge-shaped portion in the second optical waveguide core 6 is an isosceles triangle as a whole, the base length of the isosceles triangle is 1mm, and the height is 20mm.
Preferably, the length of the colored wedge-shaped portion in the second optical waveguide core 6 is 20mm.
The cross-sectional shapes of the first optical waveguide core 1 and the second optical waveguide core 6 may also be circular or rectangular, but are not limited to these shapes. Preferably, the cross section of the first optical waveguide core 1 and the second optical waveguide core 6 is square, and the side length is 1mm.
Preferably, the length of the cladding 7 is between 30 and 50mm, the cross section is rectangular as a whole, the height of the rectangle is between 2 and 3mm, and the width is between 3.5 and 5 mm.
The invention also provides a preparation method of the distributed touch sensor based on the flexible optical waveguide, which comprises the following steps:
(1) Preparing a first optical waveguide core 1 and a second optical waveguide core colored wedge portion 2;
injecting selected materials into the first molding groove 4 and the second molding groove 5 of the mold 3, and demolding and taking out after the materials are solidified; wherein the first optical waveguide inner core 1 is made of colorless transparent materials, the first forming groove 4 is cuboid, the second optical waveguide inner core colored wedge-shaped part 2 is made of colorless transparent materials mixed with colored transparent dyes, and the second forming groove 5 is wedge-shaped;
(2) Preparing a second optical waveguide core 6 based on the second optical waveguide core colored wedge portion 2;
placing the second optical waveguide core colored wedge-shaped part 2 in a first forming groove 4 of the first optical waveguide core 1, and injecting a colorless transparent material selected by the second optical waveguide colored wedge-shaped part to obtain a second optical waveguide core 6 with the same length as the first optical waveguide core 1;
(3) Preparing a cladding 7 with an inner core groove therein;
the mould for manufacturing the cladding 7 is used for placing the first optical waveguide inner core 1 and the second optical waveguide inner core 6 in parallel in a cladding 7 manufacturing mould 8, injecting a selected cladding material into the mould 8, and demoulding after the material is solidified and taking out; the colorless transparent material has optical refractive index n Core(s) And optical refractive index n of cladding material Bag(s) Satisfying the frustrated total internal reflection condition;
(4) A distributed tactile sensor package based on a flexible optical waveguide;
the first optical waveguide core 1 and the second optical waveguide core 6 are placed in said grooves, i.e. the first optical waveguide core 1 is placed in the first groove 9 of the cladding 7 and the second optical waveguide core 6 is placed in the second groove 10 of the cladding 7. And the two ends of the cladding groove are respectively connected with a light source and a photoelectric detector, and are placed in a packaging die 12, and the cladding material is adopted to package the optical waveguide sensor so as to form a finished optical waveguide sensor 13.
The colorless transparent material in the preparation method is preferably water white transparent polyurethane which does not contain mercury and phthalate; the colored transparent dye is preferably a liquid polyurethane colorant;
preferably, the number of the second optical waveguide colored wedge-shaped portions 2 is plural, and different colors and different concentrations of dyes are selected for the second optical waveguide colored wedge-shaped portions 2 among the plural so that different second optical waveguide colored wedge-shaped portions 2 generate different light absorption.
Preferably, the cladding material is polydimethylsiloxane or polydimethylsiloxane mixed with an opaque pigment.
The invention also provides a touch perception method of the distributed touch sensor based on the flexible optical waveguide, which comprises the following specific steps:
1) Calculating the optical loss of the first optical waveguide core 1 according to the input light intensity of the input end of the first optical waveguide core 1 and the light intensity detected by the photoelectric receiver of the first optical waveguide core 1; also, the optical loss of the second optical waveguide core 6 is calculated based on the input light intensity of the input end of the second optical waveguide core 6 and the light intensity detected by the photoelectric receiver of the second optical waveguide core 6;
2) Obtaining the deformation quantity on the first optical waveguide inner core 1 according to the fitting relation between the optical loss and the deformation quantity of the first optical waveguide inner core 1, and obtaining a corresponding pressure value;
3) According to the series fitting relation between the optical loss and the deformation quantity at different positions of the second optical waveguide inner core 6, the deformation quantity on the first optical waveguide inner core 1 is brought into the series fitting relation, and the deformation at the position corresponding to the relation can be determined when the optical loss is the same as the actual measurement result, so that the stress position data is obtained.
In general, the technical solution conceived by the present invention has the following beneficial effects compared with the prior art:
(1) The flexible optical touch sensor is manufactured by adopting copy molding, the inner core and the cladding are manufactured respectively, then the packaging is carried out, and the mold can be repeatedly used for a plurality of times, so that the flexible optical touch sensor has the advantages of easiness in manufacturing and low cost.
(2) The invention adopts the optical waveguide inner core comprising the dyeing wedge-shaped part, the absorption efficiency of different parts of the dyeing wedge-shaped part to light is different, the wedge-shaped structure makes the light loss of different positions of the waveguide different, and the synchronous continuous measurement of the contact force and the position is realized based on the optical waveguide inner core.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of an embodiment of the present invention.
Fig. 2 is a flow chart of the manufacturing method according to the embodiment of the invention.
FIG. 3 is a cross-sectional view of a sensor according to an embodiment of the invention.
FIG. 4 is a second cross-sectional view of a sensor according to an embodiment of the invention
The optical fiber comprises a 1-first optical waveguide inner core, a 2-second optical waveguide inner core colored wedge-shaped part, a 3-first optical waveguide and second optical waveguide mold, a 4-first optical waveguide mold, a 5-first optical waveguide and second optical waveguide colored wedge-shaped part mold, a 6-second optical waveguide, a 7-cladding layer, an 8-cladding layer mold, a 9-cladding layer groove, a 10-cladding layer groove, an 11-unpackaged sensor, a 12-packed mold and a 13-touch sensor.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments, and all other embodiments obtained by persons of ordinary skill in the art without making any inventive effort based on the embodiments of the present invention are within the scope of protection of the present invention.
The terms "first" and "second" are used herein to distinguish between different components, and it should be noted that there is no logical or chronological dependency between the terms "first" and "second", nor is it limited in number or order. It should also be noted that, although the following uses terms first, second, etc. to describe various elements, these elements should not be limited by the terms.
The following presents a simplified summary of key terms or abbreviations that may be used in accordance with an embodiment of the present invention.
Tactile sensor: a sensor imitates human touch. Haptic sensation is one of the basis for human interaction with the outside world. With the progress of high polymer materials and the development of microelectronic technology in recent years, the touch sensor has been widely applied to the fields of industrial production, artificial limbs, virtual reality technology and the like.
Optical waveguide: also known as a dielectric optical waveguide, is a dielectric device that guides light waves to propagate therein.
Cladding: refers to a layer of optical material covered outside the core of the optical fiber for transmitting light waves.
Frustrated total internal reflection: in the case of total internal reflection, the light beam is incident on the optically dense medium from the optically dense medium, and the incident angle of the light beam is greater than the critical angle, and the incident light beam is totally reflected back into the optically dense medium.
As shown in fig. 1, a distributed tactile sensor based on a flexible optical waveguide in this embodiment mainly includes: a first optical waveguide core 1, a second optical waveguide core 6, and a cladding 7, the cladding 7 completely surrounding the first optical waveguide core 1 and the second optical waveguide core 6;
the first optical waveguide core 1 and the second optical waveguide core 6 are arranged in parallel and spaced apart within the cladding 7. The term "spaced arrangement" in the present invention means that the first optical waveguide core 1 and the second optical waveguide core 6 are separated by the cladding 7 to avoid crosstalk of the transmission light in the first optical waveguide core 1 and the second optical waveguide core 6.
The input end of the first optical waveguide core 1 is connected with a first light source or an external optical fiber 14, and the output end of the first optical waveguide core 1 is connected with a photoelectric detector or an external optical fiber 15. Light emitted by the first light source is transmitted through the first optical waveguide core 1 and then received by the first photodetector. The core widths of the first optical waveguide cores 1 are the same, i.e. the first optical waveguide cores 1 have uniform widths along a first direction, the first direction being a direction in which the optical waveguide input end points to the optical waveguide output end.
Referring in conjunction with fig. 4, fig. 4 shows a second cross-sectional view of the tactile sensor 13. The second cross-sectional view is orthogonal to the cross-section of the first cross-sectional view. The first optical waveguide core 1 is provided with a square cross section, and the width of the core is the width L1 shown in fig. 4. The core widths L1 of the first optical waveguide core 1 at different positions are all the same.
The input end of the second optical waveguide core 6 is connected with a second light source or external optical fiber 16, and the output end of the second optical waveguide core is connected with a second photoelectric detector or external optical fiber 17. The light emitted by the second light source is transmitted through the second optical waveguide core 6 and then received by the second photodetector. The second optical waveguide core 6 has a colored wedge-shaped portion therein, which has a varying core width along the first direction. At least two positions in the second optical waveguide core 6 are made different in color, and at least two positions in the colored wedge-shaped portion of the second optical waveguide core are made different in core width.
The refractive index of the first optical waveguide core 1 and the second optical waveguide core 6 is greater than the refractive index of the outer layer of the cladding 7, so that frustrated total internal reflection is generated at the interface between the first optical waveguide core 1 and the second optical waveguide core 6 and the cladding 7. The refractive indices of the first optical waveguide core 1 and the second optical waveguide core 6 may be the same or different. The case where the refractive indices are the same in this embodiment will be described.
Fig. 3 is a first cross-sectional view of a tactile sensor 13 provided in an exemplary embodiment of the invention. As shown in fig. 3, the length of the first optical waveguide core 1 in this embodiment is 30mm. The cross section of the first optical waveguide inner core is square, and the side length is 1mm. The length of the colored wedge-shaped part in the second optical waveguide core 6 is 20mm. The whole longitudinal section of the colored wedge-shaped part in the second optical waveguide inner core 6 is an isosceles triangle, the bottom side of the isosceles triangle is 1mm, and the height is 20mm. The length of the cladding 7 is 30-50mm, the whole cross section is rectangular, the height of the rectangle is 2-3mm, and the width of the rectangle is 3.5-5 mm.
The cross-sectional shape of the first optical waveguide core 1 in this embodiment may also be circular or rectangular, but is not limited to these shapes.
Fig. 2 is a flowchart of a method for manufacturing a touch sensor according to an embodiment of the invention, as shown in fig. 2, the method includes the following four steps:
(1) Preparing a first optical waveguide core 1 and a second optical waveguide core colored wedge portion 2; as shown in fig. 2 (a), the first optical waveguide core 1 and the second optical waveguide core colored wedge-shaped portion 2 are manufactured by injecting a selected material into the first molding grooves 4 and 5 of the mold 3, and demolding after the material is solidified. Wherein the first optical waveguide inner core 1 is made of colorless transparent materials, the first forming groove 4 is cuboid, the second optical waveguide inner core colored wedge-shaped part 2 is made of colorless transparent materials mixed with colored transparent dyes, and the second forming groove 5 is wedge-shaped.
The colorless transparent material in the embodiment is water white transparent polyurethane which does not contain mercury and phthalate; the colored transparent dye is liquid polyurethane colorant.
Alternatively, the second optical waveguide colored wedge-shaped portion 2 may be selected from different colors and different concentrations of dyes, and the number of the second optical waveguide colored wedge-shaped portions 2 may be adjusted from 1 to N.
(2) Preparing a second optical waveguide core 6 based on the second optical waveguide core colored wedge portion 2; as shown in fig. 2 (a), the second optical waveguide core colored wedge-shaped portion 2 is placed in the first molding groove 4 of the first optical waveguide core 1, and a colorless transparent material selected for the second optical waveguide colored wedge-shaped portion is injected to obtain a second optical waveguide core 6 having the same length as the first optical waveguide core 1.
(3) Preparing a cladding 7 with an inner core groove therein; as shown in fig. 2 (b), the mold for producing the clad layer 7 is configured such that the first optical waveguide core 1 and the second optical waveguide core 6 are placed in parallel in a mold 8 for producing the clad layer 7, a selected clad material is injected into the mold 8, and the mold is removed after the material is cured.
The main component of the cladding material is polydimethylsiloxane. To reduce optical transmission losses, the cladding material may be mixed with an opaque pigment. The optical refractive index n of the inner core material Core(s) And optical refractive index n of cladding material Bag(s) The condition of frustrated total internal reflection is satisfied to ensure the light transmission capability of the optical waveguide.
(4) The core is placed in the groove, i.e. the first optical waveguide core 1 is placed in the first groove 9 of the cladding 7 and the second optical waveguide core 6 is placed in the second groove 10 of the cladding 7. And the two ends of the cladding groove are respectively connected with a light source and a photoelectric detector, as shown in fig. 2 (c), and are placed in a packaging mold 12, and the optical waveguide sensor is packaged by adopting cladding materials to form a finished optical waveguide sensor 13.
FIG. 1 is a schematic diagram of a distributed haptic sensation method based on a flexible optical waveguide provided by an example of the present invention. Since the refractive index of the inner layers of the first optical waveguide core 1 and the second optical waveguide core 6 is larger than the refractive index of the cladding material, light is confined to be transmitted in the first optical waveguide core 1 and the second optical waveguide core 6. When the flexible optical waveguide is deformed by external disturbance as shown in fig. 1, a part of light transmitted in the first optical waveguide core 1 and the second optical waveguide core 6 escapes from the optical waveguide due to failure under the condition of frustrated total internal reflection. The amount of light escaping is related to the amount of deformation, and since the core width of the first optical waveguide core 1 is uniform, when an external force is deformed in contact with the waveguide, the deformation of the optical path is independent of the contact position of the external force, and is related only to the magnitude of the external force. The deformation or contact force of the flexible optical waveguide can thus be calculated from the optical loss of the optical waveguide.
For optical waveguides containing dyed wedge portions, the transparent dye doped optical waveguides have a stronger absorption of transmitted light than undoped optical waveguides, and the dyed wedge portions have a varying core width. When the second optical waveguide core 6 is moved to the tactile position 1 or the tactile position 2 with the same amount of force, since the optical loss of the first optical waveguide core 1 is uniform, but the optical loss by the second optical waveguide core 6 is non-uniform, the optical loss on the side of the core having a color and a large width is relatively large. The light intensity loss of the optical waveguide comprising the dyed wedge-shaped portion is correlated with the contact position, from which the deformation position of the flexible optical waveguide can be calculated by decoupling. Thus realizing the double detection of the pressure value and the stress position.
The specific steps of the touch sensing method of the distributed touch sensor based on the flexible optical waveguide in the embodiment are as follows:
1) Calculating the optical loss of the first optical waveguide core 1 according to the input light intensity of the input end of the first optical waveguide core 1 and the light intensity detected by the photoelectric receiver of the first optical waveguide core 1; also, the optical loss of the second optical waveguide core 6 is calculated based on the input light intensity of the input end of the second optical waveguide core 6 and the light intensity detected by the photoelectric receiver of the second optical waveguide core 6;
2) Obtaining the deformation quantity on the first optical waveguide inner core 1 according to the fitting relation between the optical loss and the deformation quantity of the first optical waveguide inner core 1, and obtaining a corresponding pressure value;
3) According to the series fitting relation between the optical loss and the deformation quantity at different positions of the second optical waveguide inner core 6, the deformation quantity on the first optical waveguide inner core 1 is brought into the series fitting relation, and the deformation at the position corresponding to the relation can be determined when the optical loss is the same as the actual measurement result, so that the stress position data is obtained.
In summary, in the touch sensor provided in this embodiment, the width of the core body of the first optical waveguide inner core in the first direction is consistent, the color of the core body of the second optical waveguide inner core is set to be different in at least two positions in the first direction, the width of the colored wedge-shaped portion of the second optical waveguide inner core is set to be different in at least two positions in the first direction, the external force is measured by using the first optical waveguide inner core, and the contact position of the external force is measured by using the second optical waveguide inner core, so that the dual detection of the pressure value and the stress position is realized.
The above description is only a simple embodiment of the present patent, but the protection scope of the present patent is not limited thereto, and any person skilled in the art can make equivalent substitutions or changes according to the technical solution of the present patent and the inventive concept thereof within the scope of the disclosure of the present patent, which belongs to the protection scope of the present patent.
Claims (10)
1. A distributed tactile sensor based on a flexible optical waveguide, the tactile sensor comprising: a first optical waveguide core (1), a second optical waveguide core (6) and a cladding (7), the cladding (7) completely surrounding the first optical waveguide core (1) and the second optical waveguide core (6);
the first optical waveguide inner core (1) and the second optical waveguide inner core (6) are arranged in parallel and separated in the cladding (7); the input end of the first optical waveguide inner core (1) is connected with a first light source or an external optical fiber (14), and the output end of the first optical waveguide inner core (1) is connected with a photoelectric detector or an external optical fiber (15); the core widths of the first optical waveguide inner cores (1) are the same, namely the widths of the first optical waveguides inner cores (1) are uniform along a first direction, and the first direction is the direction that the optical waveguide input end points to the optical waveguide output end;
the input end of the second optical waveguide inner core (6) is connected with a second light source or an external optical fiber (16), and the output end of the second optical waveguide inner core is connected with a second photoelectric detector or an external optical fiber (17); the second optical waveguide core (6) comprises a colored wedge-shaped part, wherein the colored wedge-shaped part has a variable core width along a first direction;
the refractive index of the first optical waveguide inner core (1) and the second optical waveguide inner core (6) is larger than the outer refractive index of the cladding (7), so that the interfaces between the first optical waveguide inner core (1) and the second optical waveguide inner core (6) and the cladding (7) generate frustrated total internal reflection.
2. The distributed tactile sensor based on flexible optical waveguides according to claim 1, characterized in that the longitudinal section of the colored wedge-shaped portion in the second optical waveguide core (6) is in the form of an isosceles triangle as a whole, the base of which is 1mm and the height of which is 20mm.
3. A distributed tactile sensor based on flexible optical waveguides according to claim 1, characterized in that the length of the coloured wedge-shaped portion in the second optical waveguide core (6) is 20mm.
4. The distributed tactile sensor based on flexible optical waveguides according to claim 1, wherein the cross section of the first optical waveguide core (1) and the second optical waveguide core (6) is square as a whole and the side length is 1mm.
5. A distributed tactile sensor based on flexible optical waveguides according to claim 1, characterized in that the cladding (7) has a length of between 30 and 50mm, a rectangular overall cross section, a height of between 2 and 3mm and a width of between 3.5 and 5 mm.
6. A method of manufacturing a distributed tactile sensor based on flexible optical waveguides as claimed in claim 1, characterized in that the method comprises the steps of:
(1) Preparing a first optical waveguide core (1) and a second optical waveguide core colored wedge-shaped portion (2);
injecting selected materials into a first molding groove (4) and a second molding groove (5) of the mold (3), and demolding and taking out after the materials are solidified; wherein the first optical waveguide inner core (1) is made of colorless transparent materials, the first forming groove (4) is cuboid, the second optical waveguide inner core colored wedge-shaped part (2) is made of colorless transparent materials mixed with colored transparent dyes, and the second forming groove (5) is wedge-shaped;
(2) -preparing a second optical waveguide core (6) based on said second optical waveguide core colored wedge-shaped portion (2);
placing the second optical waveguide core colored wedge-shaped part (2) in a first forming groove (4) of the first optical waveguide core (1), and injecting a colorless transparent material selected for the second optical waveguide colored wedge-shaped part to obtain a second optical waveguide core (6) with the same length as the first optical waveguide core (1);
(3) Preparing a cladding (7) with an inner core groove therein;
the mould for manufacturing the cladding (7) is used for placing the first optical waveguide inner core (1) and the second optical waveguide inner core (6) in parallel in a cladding (7) manufacturing mould (8), injecting a selected cladding material into the mould (8), and demoulding and taking out after the material is solidified; the colorless transparent material has optical refractive index n Core(s) And optical refractive index n of cladding material Bag(s) Satisfying the frustrated total internal reflection condition;
(4) A distributed tactile sensor package based on a flexible optical waveguide;
placing a first optical waveguide inner core (1) and a second optical waveguide inner core (6) in the grooves, namely placing the first optical waveguide inner core (1) in a first groove (9) of a cladding (7), and placing the second optical waveguide inner core (6) in a second groove (10) of the cladding (7); and two ends of the cladding groove are respectively connected with a light source and a photoelectric detector, and are placed in a packaging die (12), and the optical waveguide sensor is packaged by adopting cladding materials to form a finished optical waveguide sensor (13).
7. The method for manufacturing a distributed touch sensor based on a flexible optical waveguide according to claim 6, wherein the colorless transparent material is water-white transparent polyurethane free of mercury and phthalate; the colored transparent dye is liquid polyurethane colorant.
8. The method for manufacturing a distributed touch sensor based on flexible optical waveguides according to claim 6, wherein the number of the second optical waveguide colored wedge-shaped parts (2) is plural, and different colors and different concentrations of dyes are selected for the second optical waveguide colored wedge-shaped parts (2) among the plural to enable different second optical waveguide colored wedge-shaped parts (2) to generate different light absorption.
9. The method of manufacturing a distributed touch sensor based on flexible optical waveguides according to claim 6, wherein the cladding material is polydimethylsiloxane or polydimethylsiloxane mixed with opaque pigments.
10. A method of haptic sensations based on a distributed tactile sensor according to claim 1, characterized in that it comprises the following specific steps:
(1) Calculating the optical loss of the first optical waveguide inner core (1) according to the input light intensity of the input end of the first optical waveguide inner core (1) and the light intensity detected by the photoelectric receiver of the first optical waveguide inner core (1); likewise, calculating the optical loss of the second optical waveguide core (6) based on the input optical intensity at the input end of the second optical waveguide core (6) and the optical intensity detected by the optical receiver of the second optical waveguide core (6);
(2) Obtaining the deformation quantity on the first optical waveguide inner core (1) according to the fitting relation between the optical loss and the deformation quantity of the first optical waveguide inner core (1), and obtaining a corresponding pressure value;
(3) According to a series fitting relation of the optical loss and the deformation quantity at different positions of the second optical waveguide inner core (6), the deformation quantity on the first optical waveguide inner core (1) is brought into the series fitting relation, and deformation at the position corresponding to the relation can be determined when the optical loss is the same as an actual measurement result, so that stress position data are obtained.
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