CN111829432A - A Soft Curvature Sensor with Double-layer Sensing Structure that Can Be Used Modularly - Google Patents

Abstract

The invention discloses a soft body curvature sensor with a double-layer sensing structure and capable of being used in a modularized mode, and relates to the technical field of measurement; upside protective layer, secondary sensing layer and upside intermediate level set gradually from top to bottom, and upside protective layer, upside intermediate level and downside intermediate level connect gradually, and secondary sensing layer includes a plurality of secondary sensing grids, and a plurality of secondary sensing grids set gradually along the length direction on main sensing layer, and the both ends of each secondary sensing grid are connected with a wire respectively. The soft curvature sensor with the double-layer sensing structure and capable of being used in a modularized mode can be applied to the condition that the bending condition is a one-way single curvature or a one-way non-single curvature, and detection accuracy is improved.

Description

A Soft Curvature Sensor with Double-layer Sensing Structure for Modular Use

technical field

The invention relates to the technical field of measurement, in particular to a soft curvature sensor with a double-layer sensing structure that can be used modularly.

Background technique

Soft electronic materials are developed on the basis of traditional electronic materials, and their progress in performance, function, and versatility can realize applications that cannot be realized under traditional silicon technology. The biggest feature of products made of soft electronic materials is flexibility. In the hot emerging fields such as soft robotics, wearable bio-monitoring, and human-computer interaction, products with flexibility can be used.

Intelligence has always been the goal pursued by robots, including soft robots, and perception is a necessary ability for intelligence. The perception of a soft robot includes its own motion estimation, contact modeling, and mapping of the surrounding environment. In traditional solutions, highly specialized rigid sensors can meet most of the requirements, but when used in soft robots, the intervention of rigid sensors greatly reduces the flexibility of the soft robot, and not only interferes with the motion of the robot itself, but the measured data are not accurate enough. The emergence of soft sensors is to solve this problem. The sensors directly made of soft materials can minimally affect the motion of the soft robot. In addition, the consistent posture of the two also enables the sensors to provide accurate real-time data.

In the current soft robots, bending is the main form of motion, but due to the immaturity of soft curvature sensor technology, the control of soft robots is generally forced to choose open-loop control, and the accuracy is far less than closed-loop control. In addition, the sensing structure of most soft curvature sensors generally has only one layer, and the measured result has only one data, and only a single curvature can be obtained. The bending situation of the soft robot is not perfect, and a single curvature is far from being able to provide In the complete bending situation, in applications with high precision requirements, the soft sensor of the single-layer sensing structure can no longer meet the demand.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a software curvature sensor with a double-layer sensing structure that can be used modularly.

For achieving the above object, the present invention provides the following scheme:

The present invention provides a soft curvature sensor with a double-layer sensing structure that can be used in modules. a protective layer and a lower protective layer, the intermediate layer includes an upper intermediate layer and a lower intermediate layer, the sensing layer includes a primary sensing layer and a secondary sensing layer; the lower intermediate layer, the main sensing layer The sensing layer and the lower protective layer are arranged sequentially from top to bottom, the lower intermediate layer and the lower protective layer are connected, and the two ends of the main sensing layer are respectively connected with one of the wires, The primary sensing layer is arranged along the longitudinal extension of the lower intermediate layer; the upper protective layer, the secondary sensing layer and the upper intermediate layer are arranged in sequence from top to bottom, and the upper The protective layer, the upper middle layer and the lower middle layer are connected in sequence, the secondary sensing layer includes a plurality of secondary sensing grids, and a plurality of the secondary sensing grids are arranged along the main The length directions of the sensing layers are arranged in sequence, and two ends of each of the secondary sensing grids are respectively connected with one of the wires.

Preferably, the main sensing layer includes a first channel cavity and liquid metal disposed in the first channel cavity, and the first channel cavity is disposed in the lower middle layer and the lower side Between the protective layers, the first channel cavity is arranged along the longitudinal extension of the lower middle layer.

Preferably, the secondary sensing grid includes a second channel cavity and liquid metal disposed in the second channel cavity, and the second channel cavity is disposed in the upper protective layer and the Between the upper middle layer, the length direction of the second channel cavity is perpendicular to the length direction of the first channel cavity.

Preferably, both the first channel cavity and the second channel cavity are detour-type channel cavities, the two ends of the first channel cavity are respectively provided with one of the wires, and the second channel cavity is Two ends of the cavity are respectively provided with one of the wires.

Preferably, the two wires at both ends of the first channel cavity are located on the same side of the lower middle layer, and the two wires at both ends of the second channel cavity are located on the upper middle layer. same side.

Preferably, the liquid metal is a liquid gallium indium tin alloy.

Preferably, the upper protective layer, the upper intermediate layer, the lower intermediate layer and the lower protective layer are all made of PDMS.

Preferably, the upper protective layer is bonded to the upper surface of the upper intermediate layer through an adhesive, and the upper intermediate layer is bonded to the upper surface of the lower intermediate layer through an adhesive, so The lower intermediate layer is bonded to the upper surface of the lower protective layer by an adhesive.

The present invention has achieved the following technical effects with respect to the prior art:

The software curvature sensor provided by the present invention has a double-layer sensing structure and can be used modularly. When the bending condition is a one-way non-single curvature, when the measured piece is bent and deformed, the main sensing layer can be obtained according to the relative change of resistance. The basic curvature of the bending condition of the test piece, the secondary sensing layer obtains the corrected curvature at multiple positions of the bending condition of the tested piece according to the relative change of the resistance of multiple secondary sensing grids, and performs local correction on the basic curvature. In this way, the real bending situation is obtained and the detection accuracy is improved. When the bending condition is one-way single curvature, the sensor body can be disassembled from the lower middle layer and the upper middle layer, the longitudinal soft curvature sensor containing the primary sensing layer and the lateral soft curvature sensor containing the secondary sensing layer Can work independently. The invention can solve the problem of complete curvature sensing that urgently needs to be solved in the fields of soft robots, wearable biological monitoring, human-computer interaction, etc. The two-layer structure design of the sensing layer can not only provide single curvature information, but also provide local curvature information. Curvature correction information, so as to describe a non-single curvature curve, perceive the real complete bending situation, and use the method in a modular way.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic structural diagram of a software curvature sensor with a double-layer sensing structure that can be modularized and used provided by the present invention;

2 is a schematic structural diagram of a sensor body in the present invention;

3 is a schematic structural diagram of a longitudinal soft body curvature sensor in the present invention;

FIG. 4 is a schematic structural diagram of a lateral soft body curvature sensor in the present invention.

Description of reference numerals: 1. Conductor; 2. Sensor body; 3. Sensing layer; 31. Primary sensing layer; 32. Secondary sensing layer; 321. Secondary sensing grid; 4. Protective layer; 41 42, the upper protective layer; 5, the middle layer; 51, the lower middle layer; 52, the upper middle layer.

Detailed ways

The technical solutions in 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. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a soft curvature sensor with a double-layer sensing structure that can be used modularly.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1-FIG. 4, this embodiment provides a soft curvature sensor with a double-layer sensing structure that can be used modularly, including a sensor body 2 and a plurality of wires 1, and the sensor body 2 includes a protective layer 4, an intermediate layer 5 and the sensing layer 3, the protective layer 4 includes an upper protective layer 42 and a lower protective layer 41, and the intermediate layer 5 includes an upper intermediate layer 52 and a lower intermediate layer 51. By dividing the intermediate layer 5 into two layers, it is convenient to Implementing a modular use manner, the sensing layer 3 includes a primary sensing layer 31 and a secondary sensing layer 32 . The lower intermediate layer 51, the main sensing layer 31 and the lower protective layer 41 are arranged in order from top to bottom, the lower intermediate layer 51 and the lower protective layer 41 are connected, and the lower intermediate layer 51 is used to seal the main sensing layer 31 and isolate the secondary sensing layer 32, the lower protective layer 41 is used to seal the primary sensing layer 31, separate the primary sensing layer 31 from the external environment and play a protective role, the two ends of the primary sensing layer 31 A wire 1 is connected respectively, and the resistance value information of the main sensing layer 31 is transmitted to the external circuit through the wire 1. The main sensing layer 31 is arranged along the longitudinal extension of the lower middle layer 51; the upper protective layer 42, the secondary transmission The sensing layer 32 and the upper intermediate layer 52 are arranged in order from top to bottom, the upper protective layer 42 , the upper intermediate layer 52 and the lower intermediate layer 51 are connected in sequence, and the upper intermediate layer 52 is used to seal the secondary sensing layer 32 And isolate the main sensing layer 31, the upper protective layer 42 is used to seal the secondary sensing layer 32, separate the secondary sensing layer 32 from the external environment and play a protective role, and the secondary sensing layer 32 includes multiple layers. A plurality of secondary sensing grids 321 are arranged in sequence along the length direction of the primary sensing layer 31 , and two ends of each secondary sensing grid 321 are respectively connected with a wire 1 . 1. Transmit the resistance value information of each secondary sensing grid 321 to the external circuit.

When the bending condition is a one-way non-single curvature, the measured piece is bent and deformed, the primary sensing layer 31 obtains the basic curvature of the measured piece according to the relative change in resistance, and the secondary sensing layer 32 is based on multiple secondary transmissions. The relative change of the resistance of the sensing grid 321 obtains the corrected curvature at multiple positions of the bending condition of the tested piece, and locally corrects the basic curvature, thereby obtaining the real bending condition and improving the detection accuracy. When the bending condition is unidirectional and single curvature, the sensor body 2 can be detached from the lower middle layer 51 and the upper middle layer 52, and the lower protective layer 41, the main sensing layer 31 and the lower middle layer 51 are combined into a A longitudinal soft curvature sensor can be used alone to measure a single large curvature in one direction; the upper protective layer 42, the secondary sensing layer 32 and the upper middle layer 52 are combined into a transverse soft curvature sensor, which can be used alone to measure a one-way curvature A single small curvature, that is, the longitudinal soft body curvature sensor containing the primary sensing layer 31 and the lateral soft body curvature sensor containing the secondary sensing layer 32 can independently complete the corresponding work.

As shown in FIG. 3 , the main sensing layer 31 includes a first channel cavity and liquid metal disposed in the first channel cavity, and the first channel cavity is disposed between the lower middle layer 51 and the lower protective layer 41 , the first channel cavity is arranged along the longitudinal extension of the lower middle layer 51 .

As shown in FIG. 4 , the secondary sensing grid 321 includes a second channel cavity and liquid metal disposed in the second channel cavity, and the second channel cavity is disposed on the upper protective layer 42 and the upper intermediate layer 52 In between, the length direction of the second channel cavity is perpendicular to the length direction of the first channel cavity. There are three secondary sensing grids 321 in this embodiment, and the three secondary sensing grids 321 are uniformly arranged along the length direction of the primary sensing layer 31 .

In this specific embodiment, the first channel cavity and the second channel cavity are both detoured channel cavities, two ends of the first channel cavity are respectively provided with a wire 1, and two ends of the second channel cavity are respectively provided with a wire 1. One wire 1 is provided.

In this embodiment, the two wires 1 at both ends of the first channel cavity are located on the same side of the lower middle layer 51 , and the two wires 1 at both ends of the second channel cavity are located on the same side of the upper middle layer 52 .

In this embodiment, the liquid metal is a liquid gallium indium tin alloy. Liquid metal used as a material itself has the advantages of low viscosity, high electrical conductivity and low vapor pressure. The low viscosity reduces the air gap between the sensing material and the sealing material. High conductivity can improve the sensitivity of the sensor. The low vapor pressure keeps the liquid metal from volatilizing excessively, increasing the safety factor for operators and users. In addition, compared with conductive nanocomposites and conductive organic solutions, liquid metal has no drift and nonlinearity in the measurement results.

In this specific embodiment, the upper protective layer 42 , the upper intermediate layer 52 , the lower intermediate layer 51 and the lower protective layer 41 are all made of PDMS. The use of PDMS as a manufacturing material can make the soft curvature sensor have the most important flexibility, buffer protection against external pressure, impact and stretch, and seal the sensing layer material.

In this specific embodiment, the upper protective layer 42 is bonded to the upper surface of the upper middle layer 52 through an adhesive, the upper middle layer 52 is bonded to the upper surface of the lower middle layer 51 through an adhesive, and the lower The side intermediate layer 51 is bonded to the upper surface of the lower side protective layer 41 by an adhesive.

Specifically, the DUT is directly fabricated by 3D printing. The soft curvature sensor in this embodiment is embedded and installed in the pore of the DUT, and is sealed and fixed with PDMS material. The soft curvature sensor bends following the bending of the DUT. Measure its bending.

When making the soft curvature sensor in this example, first use a 3D printer to print out the protective layer mold, mix the PDMS material, pour it into the mold, wait for it to be completely cured, use a scraper to cut off the excess material, and the upper side The shapes of the protective layer 42 and the lower protective layer 41 are exactly the same as the manufacturing method, and both the upper protective layer 42 and the lower protective layer 41 are flat rectangular parallelepipeds. The channel shapes of the primary sensing layer 31 and the secondary sensing layer 32 are printed on the mold using a 3D printer, and the PDMS materials are poured respectively. After being completely cured, the lower middle layer 51 containing the first channel groove is obtained. and an upper intermediate layer 52 containing a plurality of second channel grooves.

The lower protective layer 41 and the lower intermediate layer 51 are bonded with an adhesive, the first channel groove of the lower intermediate layer 51 is set downward, and the lower protective layer 41 covers the lower surface of the lower intermediate layer 51, A first channel cavity is formed between the lower middle layer 51 and the lower protective layer 41. After the adhesive is fully bonded, the liquid gallium indium tin alloy is injected into the first channel cavity using a syringe to form a main channel. Sensing layer 31; the upper protective layer 42 and the upper intermediate layer 52 are bonded with an adhesive, the second channel groove of the upper intermediate layer 52 is set upward, and the upper protective layer 42 covers the upper intermediate layer 52, so that a plurality of second channel cavities are formed between the upper protective layer 42 and the upper intermediate layer 52. After the adhesive is fully bonded, the liquid gallium indium tin alloy is injected into the plurality of second channel cavities using a syringe. In the channel cavity, the secondary sensing layer 32 is formed; finally, the lower side intermediate layer 51 and the upper side intermediate layer 52 are bonded with adhesive. After the bonding is completed, the complete soft curvature sensor is completed.

The specific working principle is as follows: when the sensing layer 3 is bent and deformed, the resistance value of the liquid metal material in the sensing layer 3 will change. It is necessary for the sensing layer 32 to obtain the corrected curvatures at the three positions of the bending condition of the test piece according to the relative resistance changes of the three secondary sensing grids 321, and to locally correct the basic curvature, so as to obtain the true bending Happening. The use of the soft body curvature sensor in this embodiment has a modular approach. When the bending condition is one-way single curvature, only the longitudinal soft body curvature sensor or the lateral soft body curvature sensor can complete the measurement task. When the bending condition is one-way non-unidirectional curvature For a single curvature, a complete soft body curvature sensor can complete the measurement task.

It can be seen that this embodiment can solve the problem of complete curvature sensing that urgently needs to be solved in the fields of soft robots, wearable biological monitoring, human-computer interaction, etc. The two-layer structure design of the sensing layer 3 can not only give a single curvature information, but also It can give local curvature correction information, so as to describe a non-single curvature curve, perceive the real complete bending situation, and use the method in a modular way.

In this specification, specific examples are used to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; There will be changes in the specific implementation manner and application scope of the idea of the invention. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. A soft curvature sensor with a double-layer sensing structure and capable of being used in a modularized mode is characterized by comprising a sensor body and a plurality of wires, wherein the sensor body comprises a protective layer, a middle layer and a sensing layer, the protective layer comprises an upper protective layer and a lower protective layer, the middle layer comprises an upper middle layer and a lower middle layer, and the sensing layer comprises a main sensing layer and a secondary sensing layer; the lower side middle layer, the main sensing layer and the lower side protective layer are sequentially arranged from top to bottom, the lower side middle layer is connected with the lower side protective layer, two ends of the main sensing layer are respectively connected with one lead, and the main sensing layer is arranged along the longitudinal extension of the lower side middle layer; the upside protective layer the secondary sensing layer with the upside intermediate level sets gradually from top to bottom, the upside protective layer the upside intermediate level with the downside intermediate level connects gradually, the secondary sensing layer includes a plurality of secondary sensing grids, and is a plurality of secondary sensing grid follows the length direction on main sensing layer sets gradually, each the both ends of secondary sensing grid are connected with one respectively the wire.

2. The modularly usable soft curvature sensor having a two-layer sensing architecture as claimed in claim 1, wherein said primary sensing layer comprises a first channel cavity and a liquid metal disposed in said first channel cavity, said first channel cavity disposed between said lower intermediate layer and said lower protective layer, said first channel cavity disposed along a longitudinal extension of said lower intermediate layer.

3. The modularly usable soft curvature sensor with two-layer sensing architecture as claimed in claim 2, wherein said secondary sensing grid comprises a second channel cavity and a liquid metal disposed in said second channel cavity, said second channel cavity being disposed between said upper protective layer and said upper intermediate layer, the length direction of said second channel cavity being perpendicular to the length direction of said first channel cavity.

4. The modularly usable soft curvature sensor with two-layer sensing structure as claimed in claim 3, wherein said first channel cavity and said second channel cavity are both circuitous channel cavities, and one of said wires is disposed at each end of said first channel cavity, and one of said wires is disposed at each end of said second channel cavity.

5. The modularly usable soft curvature sensor with two layers of sensing architecture as claimed in claim 4, wherein said two wires at both ends of said first channel cavity are located on the same side of said lower middle layer and said two wires at both ends of said second channel cavity are located on the same side of said upper middle layer.

6. The modularly usable soft curvature sensor with dual layer sensing architecture of claim 3, wherein said liquid metal is liquid gallium indium tin alloy.

7. The modularly usable soft curvature sensor with two-layer sensing structure as claimed in claim 1, wherein said upper protection layer, said upper middle layer, said lower middle layer and said lower protection layer are made of PDMS.

8. The modularly usable soft curvature sensor with two-layer sensing architecture as claimed in claim 1, wherein said upper protective layer is adhered to the upper surface of said upper intermediate layer by an adhesive, said upper intermediate layer is adhered to the upper surface of said lower intermediate layer by an adhesive, and said lower intermediate layer is adhered to the upper surface of said lower protective layer by an adhesive.

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