Multifunctional flexible touch sensor with sliding sense, pressure sense and temperature sense
Technical Field
The invention belongs to the technical field of sensors, relates to a multifunctional touch sensor applied to a fake fingertip, and particularly relates to a multifunctional flexible touch sensor with sliding sense, pressure sense and temperature sense.
Background
Early prostheses relied on the human's own visual feedback channel in part instead of the tactile perception channel. Namely, the prosthesis user needs to continuously observe the interaction state of the prosthesis and the environment and adjust the gripping force of the prosthesis. The operator needs a high concentration of attention during the entire procedure and the entire procedure is relatively slow, such prostheses are not widely accepted by amputees.
With the development of sensor technology, sensors for initially measuring the interaction state of the prosthesis with the environment are mounted on the prosthesis. Representative are Otto Bock corporation, Germany, and RSL Steeper, United kingdom. Such as: sani H N and Meek S G have incorporated slip sensors in the design of prosthetic hands. The processor compares and analyzes two continuous images, measures the direction of change of the images and the displacement, obtains the relative motion state of the current object and the prosthetic hand, and accordingly adjusts the motion of the prosthetic hand.
According to the characteristics of hands, the flexible touch sensor/micro sensor array/artificial skin which is covered on the surface of the artificial limb, is suitable for the artificial limb, is large in area, soft, and has touch sensing and data processing capabilities, is an important sensing form for acquiring environmental information only second to machine vision, is a necessary medium for realizing direct action between the artificial limb and the outside, and can enable the artificial limb to have touch sense.
Disclosure of Invention
In order to solve the problems, the invention discloses a multifunctional flexible touch sensor with sliding sense, pressure sense and temperature sense, which can simultaneously detect various touch information such as temperature, pressure, sliding and the like, and has the advantages of high sensitivity, high integration of various sensors and wide application range.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a multi-functional flexible tactile sensor with a sliding sensation, a pressure sensation, and a temperature sensation, comprising:
the temperature detection module A consists of a single optical fiber, a single optical fiber luminous tube, a single optical fiber receiving tube, a reference optical fiber luminous tube and a reference optical fiber receiving tube;
a sliding sense detection module B consisting of a piezoelectric film printed with an upper electrode and a lower electrode and a single optical fiber;
the capacitive pressure sensation detection module C consists of upper and lower layers of conductive cloth and a middle flexible conductive dielectric layer;
in the temperature detection module A, a single optical fiber is woven into a net structure, first insulating paper is arranged above the single optical fiber, a reference optical fiber is positioned above the single optical fiber luminous tube, and one end of the single optical fiber is irradiated by the single optical fiber luminous tube to serve as an optical signal input port; the other end is received by a single optical fiber receiving tube and is used as an optical signal output port; one end of the reference optical fiber is irradiated by a reference optical fiber luminous tube and is used as a reference light signal input port, wherein the single optical fiber luminous tube and the reference optical fiber luminous tube are the same light source; the other end is received by a reference optical fiber receiving tube and is used as a reference optical signal output port;
in the temperature detection module A, a temperature signal is detected by utilizing a phase difference generated by a light signal received by a single optical fiber receiving tube and a reference light signal received by a reference optical fiber receiving tube;
in the sliding sensation detection module B, a mesh structure is woven by single optical fibers in the temperature detection module A; rectangular electrodes are printed on the upper surface and the lower surface of the left lower corner of the piezoelectric film, the piezoelectric film is arranged below the single optical fiber, and second insulating paper is pasted between the piezoelectric film and the single optical fiber for separation;
in the pressure sensation detection module C, flexible conductive cloth with conductive performance is stuck on the upper surface and the lower surface of the middle flexible conductive medium layer, and third insulating paper and fourth insulating paper are stuck on the surfaces of the two layers of conductive cloth for separation;
the sliding sense detection module B is arranged below the temperature detection module A, and the pressure sense detection module C is arranged below the sliding sense detection module B.
Preferably, the piezoelectric film of the sliding sensation detection module B is made of PVDF.
Preferably, the middle flexible conductive medium layer of the pressure sensation detection module C is made of PORON (polyurethane).
Preferably, the conductive cloth of the pressure detection module C is made of polyester fiber.
The invention has the beneficial effects that:
according to the temperature detection module A, the single optical fiber is woven into the net structure, so that vibration signals generated by contact between the surface of the sensor and an object are amplified, and the sensitivity of the pressure sensation detection module for detecting the sliding signals is improved.
According to the invention, all modules are combined together by utilizing a laminated structure, so that the space occupied by various sensors is reduced, and the characteristic of high integration is embodied.
The sensor is made of fully flexible materials, and in the measuring process, in order to eliminate the coupling of the pressure signal and the temperature signal of the object, the temperature detection module A and the capacitance type pressure sensation detection module C are calibrated, the data of the pressure sensation detection module is utilized to eliminate the measuring error of the temperature detection module, and the temperature measuring precision is improved.
Drawings
FIG. 1 is a vertical cross-sectional view of a multi-functional flexible tactile sensor of the present invention having a sliding sensation, a pressure sensation, and a temperature sensation;
fig. 2 is a disassembled perspective view of the multi-functional flexible tactile sensor with sliding, pressure and temperature senses of the present invention.
List of reference numerals:
2 single optical fiber; 2A single optical fiber luminous tube; 2B, single optical fiber receiving tubes; 4a piezoelectric film; a 4A electrode; 6, conductive cloth; 7, an intermediate flexible conductive medium layer; 8a reference fiber; 8A reference optical fiber luminous tube; 8B, a reference optical fiber receiving tube; 1 a first insulating paper; 3 second insulating paper; 5 third insulating paper; 9 fourth insulating paper.
Detailed Description
The present invention will be further illustrated with reference to the accompanying drawings and specific embodiments, which are to be understood as merely illustrative of the invention and not as limiting the scope of the invention.
As shown in the figure, the multifunctional flexible tactile sensor with sliding sense, pressure sense and temperature sense in the present embodiment comprises, from top to bottom: the device comprises a temperature detection module, a sliding sense detection module and a pressure sense detection module.
The mechanism for detecting the tactile information by the multifunctional flexible tactile sensor of the embodiment is as follows: when an object touches a plastic film (first insulating paper 1) on the surface of the sensor, firstly, in the temperature detection module A, along with the change of temperature, a single optical fiber 2 sends an optical signal carrying temperature information to a single optical fiber receiving tube 2B, and the temperature information is obtained according to the phase difference of the optical signals in the single optical fiber 2 and a reference optical fiber 8; secondly, in the sliding sense detection module B, as the single optical fiber 2 in the temperature detection module is of a network structure, a vibration signal generated by the contact between the surface of the sensor and an object is amplified, so that the piezoelectric property of a piezoelectric film (PVDF material) is more obvious, and the relative motion state of the object and the sensor can be obtained; and finally, in the pressure sensation detection module C, the distance between the upper conductive cloth 6 and the lower conductive cloth is changed, so that the capacitance is changed, and pressure information is obtained.
The sensor adopts a fully flexible medium, when the sensor touches an object, the object generates pressure on the optical fiber in the temperature detection module, and the phase of an optical signal in the optical fiber changes, so that the measurement of the sensor generates errors. In order to eliminate the error, the temperature detection module and the capacitance type pressure sensation detection module are calibrated, and the pressure data of the pressure sensation detection module is utilized to calibrate the detection data of the temperature module, so that the measurement precision of the sensor is improved.
Rectangular flexible electrodes 4A are printed on the upper and lower surfaces of the left lower corner of a dielectric layer (PVDF material) in the sliding sensation detection module.
And conductive cloth 6 with conductive performance is adhered to the upper surface and the lower surface of a dielectric layer (polyurethane material) in the pressure sensation detection module.
The modules are separated by first insulating paper 1, second insulating paper 3, third insulating paper 5 and fourth insulating paper 9.
Specifically, a single optical fiber 2 in the temperature detection module is woven into 3 × 3 loops, 3 loops are transversely arranged, 3 loops are longitudinally arranged, the length is 6mm, and the width is 6 mm. A single optical fiber luminous tube 2A and a single optical fiber receiving tube 2B are arranged at a position 1mm away from the two ends of the single optical fiber. The reference optical fiber 8 is positioned 2mm above the single optical fiber luminous tube 2A, the first insulating paper 1 and the second insulating paper 3 are pasted on the upper surface and the lower surface of the temperature detection module, the length is 8mm, and the width is 8 mm.
Specifically, the dielectric layer (piezoelectric film 4) in the sliding sensation detection module is made of PVDF, and has a length of 8mm, a width of 8mm, and a height of 1 mm. Rectangular electrodes are printed on the lower left corner of the surface of the medium layer, the length of each electrode is 3mm, and the width of each electrode is 2 mm. The upper and lower surfaces of the sliding sense detection module are pasted with second insulating paper 3 and third insulating paper 5, the length is 8mm, and the width is 8 mm.
Specifically, the middle flexible conductive medium layer 7 in the pressure sensation detection module is made of PORON (polyurethane), and has a length of 8mm, a width of 8mm and a height of 1 mm. Cloth (conductive cloth 6) made of polyester fiber is adhered to the upper and lower surfaces of the dielectric layer. Third insulating paper 5 and fourth insulating paper 9 are pasted on the upper surface and the lower surface of the pressure sensation detection module, the length is 8mm, and the width is 8 mm.
Specifically, add the wire in slip sense detection module electrode department, add the wire on the electrically conductive cloth of pressure sense detection module to based on flexible FPCB technique, draw the wire, the bending deformation that the sensor of being convenient for can be arbitrary has good flexibility.
Specifically, each module of the sensor is adhered together after being cured for 24 hours according to the laminated structure, so that the sensor is guaranteed to have a stable structure, and the performance is improved.
The technical means disclosed in the invention scheme are not limited to the technical means disclosed in the above embodiments, but also include the technical scheme formed by any combination of the above technical features.