阅读说明：本技术 一种柔性仿生电子皮肤感知机构 (Flexible bionic electronic skin sensing mechanism ) 是由 周艳敏 何斌 汪亚飞 王启刚 王志鹏 朱忠攀 于 2021-08-09 设计创作，主要内容包括：本发明涉及一种柔性仿生电子皮肤感知机构,包括凝胶层、PDMS隔离层和多个电容式感知单元,PDMS隔离层的顶面贴合凝胶层的底面,多个电容式感知单元均匀分布贴合在PDMS隔离层的底面,其中,每个电容式感知单元包括中间层以及贴合中间层上下两侧的电极层,电极层由PDMS材料中置入金属纤维网络构成,中间层由凝胶中混入活性炭并嵌入微结构多孔的PDMS材料构成。与现有技术相比,本发明能实现同一接触点的精确触觉定位和压觉感知,而且结构稳定性好。(The invention relates to a flexible bionic electronic skin sensing mechanism which comprises a gel layer, a PDMS (polydimethylsiloxane) isolation layer and a plurality of capacitive sensing units, wherein the top surface of the PDMS isolation layer is attached to the bottom surface of the gel layer, the capacitive sensing units are uniformly distributed and attached to the bottom surface of the PDMS isolation layer, each capacitive sensing unit comprises an intermediate layer and electrode layers attached to the upper side and the lower side of the intermediate layer, the electrode layers are formed by placing metal fiber networks in PDMS materials, and the intermediate layer is formed by mixing activated carbon in gel and embedding a microstructure porous PDMS material. Compared with the prior art, the invention can realize the accurate touch positioning and pressure perception of the same contact point and has good structural stability.)

1. The utility model provides a flexible bionical electron skin perception mechanism, its characterized in that includes gel layer (1), PDMS isolation layer (2) and a plurality of capacitanc perception unit (3), the bottom surface of gel layer (1) is laminated to the top surface of PDMS isolation layer (2), a plurality of capacitanc perception unit (3) evenly distributed laminating are in the bottom surface of PDMS isolation layer (2), wherein, every capacitanc perception unit (3) include intermediate level (32) and laminate intermediate level (32) electrode layer (31) of both sides from top to bottom, electrode layer (31) are put into the metal fiber network by the PDMS material and are constituted, intermediate level (32) are mixed active carbon and are imbedded the porous PDMS material of microstructure by the gel and constitute.

2. The flexible bionic electronic skin sensing mechanism according to claim 1, wherein the plurality of capacitive sensing units (3) are distributed in a matrix on the bottom surface of the PDMS isolation layer (2).

3. The flexible biomimetic electronic skin augmentation mechanism according to claim 1, wherein the gel layer (1) comprises BMIMBF₄A mixed gel of HEMA and zirconium oxide.

4. The flexible bionic electronic skin sensing mechanism according to claim 1, characterized in that an electrode layer (31) of the capacitance sensing unit (3) is connected with a capacitance measuring instrument;

when the gel layer (1) is provided with a contact point, the capacitance value of the capacitance sensing unit (3) at the corresponding position changes, and the pressure value of the contact point is obtained through the capacitance value measured by the capacitance measuring instrument and the corresponding relation between the preset capacitance value and the pressure value.

5. The flexible biomimetic electronic skin sensor mechanism according to claim 4, wherein the correspondence between capacitance and pressure is linear.

6. The flexible bionic electronic skin sensing mechanism according to claim 1, characterized in that a circular area is arranged on the gel layer (1), and four measuring branches are uniformly arranged on the circular edge of the circular area;

when the gel layer (1) is provided with a contact point, the position information of the contact point is obtained by calculating the data respectively measured by the four measuring branches.

7. The flexible bionic electronic skin sensing mechanism according to claim 6, wherein polar coordinates are established with a circular point of a circular area as a pole, the position information of the contact point is coordinates (p, θ), the measured data of each measuring branch is a voltage value, and the calculation expressions in p and θ in the coordinates (p, θ) are as follows:

in the formula, V₁、V₂、V₃And V₄The voltage values, c and c, measured by the four measuring branches respectively,d and e are coefficients.

8. The flexible bionic electronic skin sensing mechanism according to claim 6, wherein each measuring branch comprises a branch resistor and a voltmeter, one end of the branch resistor is connected with the circular edge of the gel layer (1), the other end of the branch resistor is connected with the power supply, the voltmeter is connected in parallel at two ends of the branch resistor, and the branch resistors of the four measuring branches have the same resistance value.

Technical Field

The invention relates to the technical field of electronic bionics, in particular to a flexible bionic electronic skin perception mechanism.

Background

The study of flexible perception began in the seventies of the twentieth century. As chemical and material science has progressed in 2000 to date, significant efforts have been made to improve and develop tactile sensors, with increased emphasis on simulating the mechanical properties of biological sensing systems. The sensing mechanisms of the touch and pressure sensing device mainly comprise a piezoelectric effect, a piezoresistive effect and a capacitance effect. Sensors based on the piezoelectric effect are generally used only to detect dynamic contact, and require an additional transistor to read and amplify signals from a sensing element, thereby having a complex configuration, a difficult manufacturing process, and high power consumption. The piezoresistive type sensor is widely used in a commercial sensor because of its simple principle and convenient reading, but its sensitivity is low, and it is difficult to detect a low voltage signal. The capacitance type sensor has lower sensitivity and sensitivity to temperature change, better output stability, wide application prospect in medical engineering, biomechanics, robotics and other subjects, and is also the current mainstream sensor.

However, the above-described sensor (tactile and pressure sensing device) still has the following problems: 1. the structure of the sensor usually adopts the forms of a flexible electrode plate and a metal copper sheet, and the metal copper sheet has poor overall flexibility and poor fitting degree with a soft input device. 2. The sensors on the flexible circuit board can only detect pressure, the touch positioning is realized by calculation through array arrangement feedback of a plurality of sensors, and the positioning precision is closely related to the distribution dispersion of the sensors, so that the precision is poor.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a flexible bionic electronic skin perception mechanism.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a flexible bionical electron skin perception mechanism, includes gel layer, PDMS isolation layer and a plurality of capacitanc perception unit, the bottom surface of the top surface laminating gel layer of PDMS isolation layer, a plurality of capacitanc perception unit evenly distributed laminating are in the bottom surface of PDMS isolation layer, and wherein, every capacitanc perception unit includes the electrode layer of both sides about intermediate level and the laminating intermediate level, the electrode layer is put into the metal fiber network by the PDMS material and is constituted, the intermediate level is sneaked into the active carbon in by the gel and is imbedded the porous PDMS material of microstructure and constitute.

Furthermore, the plurality of capacitive sensing units are distributed on the bottom surface of the PDMS isolation layer in a matrix manner.

Further, the gel layer comprises BMIMBF₄A mixed gel of HEMA and zirconium oxide.

Further, an electrode layer of the capacitance sensing unit is connected with a capacitance measuring instrument;

when the gel layer is provided with a contact point, the capacitance value of the capacitance sensing unit at the corresponding position changes, and the pressure value of the contact point is obtained through the capacitance value measured by the capacitance measuring instrument and the corresponding relation between the preset capacitance value and the pressure value.

Further, the corresponding relation between the capacitance value and the pressure value is a linear relation.

Furthermore, a circular area is arranged on the gel layer, and four measuring branches are uniformly arranged on the circular edge of the circular area;

when the gel layer is provided with the contact point, the position information of the contact point is obtained by calculating the data respectively measured by the four measuring branches.

Further, polar coordinates are established by taking a circular point of the circular area as a pole, the position information of the contact point is coordinates (rho, theta), the measured data of each measuring branch is a voltage value, and the calculation expressions in rho and theta in the coordinates (rho, theta) are as follows:

in the formula, V₁、V₂、V₃And V₄Voltage values, c, measured for four measuring branches respectivelyD and e are coefficients.

Furthermore, each measuring branch comprises a branch resistor and a voltmeter, one end of the branch resistor is connected with the circular edge on the gel layer, the other end of the branch resistor is connected with the power supply, the voltmeter is connected in parallel at two ends of the branch resistor, and the resistance values of the branch resistors of the four measuring branches are the same.

Compared with the prior art, the invention has the following beneficial effects:

the touch sensing device is provided with the gel layer and the capacitive sensing unit, touch positioning is realized through the gel layer, pressure sensing is realized through the capacitive sensing unit, and the gel layer and the capacitive sensing unit are isolated and bonded through the PDMS isolating layer, so that the touch sensing device can realize accurate touch positioning and pressure sensing of the same contact point and has good structural stability. Meanwhile, the capacitive sensing unit adopts an electrode layer consisting of PDMS and a metal fiber network, adopts the middle layer consisting of the PDMS with a porous microstructure, gel and active carbon, realizes a fully flexible structure, can be completely attached to a software input device during use, and has a good application prospect.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a graph showing the relationship between capacitance and sensed pressure.

Fig. 3 is a schematic structural diagram of a measurement branch.

Reference numerals: 1. gel layer, 2, PDMS isolating layer, 3, capacitive sensing unit, 31, electrode layer, 32, intermediate layer.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

As shown in fig. 1, the present embodiment provides a flexible bionic electronic skin sensing mechanism, which includes three layers: the top layer is a gel layer 1 and is used for realizing touch positioning; the bottom layer is provided with a plurality of uniformly distributed capacitive sensing units 3 for realizing pressure sensation sensing, and the capacitive sensing units are distributed in a matrix form in the embodiment; the middle layer is a PDMS (polydimethylsiloxane) isolation layer which is used for realizing circuit isolation and fixation, and a gel layer 1 and a capacitance sensing unit 3 are bonded.

Each capacitive sensing unit 3 includes an intermediate layer 32 and electrode layers 31 attached to the upper and lower sides of the intermediate layer 32. The electrode layer 31 is formed by a metal fiber network in a PDMS material, and the intermediate layer 32 is formed by a PDMS material with a microstructure porous embedded in gel mixed with activated carbon, so that the capacitive sensing unit 3 forms a fully flexible capacitive structure.

In the present embodiment, the gel layer 1 is a conventional conductive gel, and BMIMBF may be used₄(methylimidazolium tetrafluoroborate), HEMA (hydroxyethyl methacrylate), and zirconium oxide. The strength and the adhesiveness of the material can be adjusted through the material proportion and the manufacturing process, and the material has excellent strength matching capability. The same material as the gel layer 1 is used for the gel in the intermediate layer 32 of the capacitive sensing cell 3.

For pressure perception:

before use, the present embodiment first needs to perform a pressure sensing test on the capacitive sensing unit 3 to obtain a relationship between a capacitance value and a sensing pressure. Platinum electrodes are connected to the upper electrode layer 31 and the lower electrode layer 31 of one capacitive sensing unit 3, and a high-precision capacitance meter is connected; then applying different weights with the same contact area on the gel layer 1 to obtain and record corresponding capacitance values; and finally, calculating the corresponding pressure value of the weight to obtain a relation function of the pressure C and the capacitance value P:

C＝aP+b

in the formula, a and b are function coefficients, and a functional relationship diagram is shown in fig. 2.

When the capacitance type pressure sensor is used, when the gel layer 1 is provided with the contact points, the capacitance type sensing unit 3 deforms along with the contact points, the capacitance value of the capacitance type sensing unit 3 at the corresponding position changes, and the pressure value of the contact points is obtained according to the capacitance value measured by the capacitance measuring instrument and the corresponding relation between the measured capacitance value and the pressure value.

For haptic positioning:

haptic positioning is achieved by establishing polar coordinates. A circular area is arranged on the gel layer 1, and four measuring branches are uniformly arranged on the circular edge of the circular area. As shown in fig. 3, each measuring branch comprises a branch resistor and a voltmeter (the voltmeter is not shown), one end of the branch resistor is connected with the circular edge of the gel layer 1, and the other end of the branch resistor is connected with the power supply; the voltmeter is connected in parallel at the two ends of the branch resistance, and the branch resistance values of the four measuring branches are the same.

During the use, when having the contact point on the gel layer 1, calculate through the data that four measuring branch roads were surveyed respectively to obtain the positional information of contact point, specifically be:

establishing polar coordinates by taking a circular point of the circular area as a pole, taking the position information of the contact point as coordinates (rho, theta), taking the data measured by each measuring branch as a voltage value, and calculating expressions in rho and theta in the coordinates (rho, theta) are as follows:

in the formula, V₁、V₂、V₃And V₄The voltage values measured by the four measuring branches are respectively, and c, d and e are coefficients.

In summary, in the present embodiment, the touch positioning is realized by the gel layer 1, the pressure sensing is realized by the capacitive sensing unit 3, and the gel layer 1 and the capacitive sensing unit 3 are isolated and bonded by the PDMS isolation layer 2, so that the touch positioning and the pressure sensing at the same contact point can be realized, and the structural stability is good. Meanwhile, the capacitive sensing unit of the embodiment adopts an electrode layer consisting of PDMS and a metal fiber network, and adopts a middle layer consisting of the PDMS with a porous microstructure, gel and activated carbon, so that a fully flexible structure is realized, the capacitive sensing unit can be completely attached to a software input device during use, and the capacitive sensing unit has a good application prospect.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.