阅读说明：本技术 一种可检测多级力的柔性传感单元及制作方法 (Flexible sensing unit capable of detecting multi-level force and manufacturing method ) 是由 卢思彤 李强 陈殿生 于 2021-10-15 设计创作，主要内容包括：一种可检测多级力的柔性传感单元及制作方法,利用压容单元和压阻单元叠加封装于上封装膜和下封装膜之间；压容单元包括上极板、介电层和下极板,所述介电层安装于所述上极板和所述下极板之间；所述压阻单元包括硅胶管和液态导电合金,所述液态导电合金注入所述硅胶管中；发明通过压容单元在外力较小的范围内工作,通过压阻单元在外力较大的范围内工作,通过电容单元和电阻单元在工作中相互转换,既可以保证多级力测量的精确性,又可以提高测量力大小的范围。(A flexible sensing unit capable of detecting multi-level force and a manufacturing method thereof are disclosed, wherein a pressure-capacitance unit and a piezoresistance unit are stacked and packaged between an upper packaging film and a lower packaging film; the pressure-capacitance unit comprises an upper polar plate, a dielectric layer and a lower polar plate, wherein the dielectric layer is arranged between the upper polar plate and the lower polar plate; the piezoresistive unit comprises a silicone tube and a liquid conductive alloy, and the liquid conductive alloy is injected into the silicone tube; the invention can ensure the accuracy of multi-level force measurement and improve the range of the measured force by the mutual conversion of the capacitance unit and the resistance unit during the work through the working of the pressure-capacitance unit in the range of smaller external force, the working of the pressure-resistance unit in the range of larger external force and the mutual conversion of the capacitance unit and the resistance unit during the work.)

1. A flexible sensing unit capable of detecting multi-level force is characterized by comprising an upper packaging film, a pressure-volume unit, a piezoresistive unit and a lower packaging film; the pressure-containing unit and the pressure-resistance unit are stacked and packaged between the upper packaging film and the lower packaging film; the pressure capacity unit comprises an upper polar plate, a dielectric layer and a lower polar plate, the upper polar plate and the lower polar plate have the same structure, and the dielectric layer is arranged between the upper polar plate and the lower polar plate; the piezoresistive unit comprises a silicone tube and a liquid conductive alloy, and the liquid conductive alloy is injected into the silicone tube; the upper packaging film is connected with the upper pole plate of the pressure-capacitance unit, the lower pole plate of the pressure-capacitance unit is superposed with the upper layer of the pressure-resistance unit, and the bottom layer of the pressure-resistance unit is connected with the lower packaging film.

2. The multi-force detectable flexible sensing unit according to claim 1, wherein the structure of the upper plate and the lower plate comprises a copper foil conductive tape and a chromium sheet; the two layers of the copper foil conductive tapes are arranged side by side in an orthogonal mode, and the chromium sheets are arranged at the orthogonal positions of the two layers of the copper foil conductive tapes.

3. The multi-stage force detectable flexible sensing unit according to claim 2, wherein the copper foil conductive tape is provided with an adhesive surface, the adhesive surfaces of the two copper foil conductive tapes are oppositely arranged, and the chromium plate is fixed through the adhesive surfaces.

4. The flexible force sensing unit of claim 1, wherein the dielectric layer comprises nano-adhesive tapes, and wherein two or more layers of the nano-adhesive tapes are orthogonally stacked on top of each other.

5. The flexible sensing unit of claim 1, wherein the liquid conductive alloy is selected from an indium gallium alloy, an indium gallium tin alloy, or a bismuth indium tin alloy.

6. The flexible sensing unit of claim 1, wherein the silicone tube is configured in a spiral shape, and two sections of the silicone tube are connected in series and fit together to form a double spiral shape.

7. The flexible sensing unit of claim 6, wherein the piezoresistive unit has more than one layer of double-spiral silicone tubes, and two adjacent layers of silicone tubes are bonded by silicone.

8. A method for manufacturing a flexible sensing unit capable of detecting multi-level force is characterized in that a copper foil conductive adhesive tape is orthogonally placed, and a chromium plate is arranged at the orthogonal position to form an electrode plate; orthogonally placing the layers of the nano adhesive tapes which are placed side by side to form a dielectric layer; installing the dielectric layer between the two electrode plates to form a pressure-volume unit;

injecting liquid conductive alloy into a silicone tube, sealing two ends of the silicone tube, leading out a lead to be spiral, connecting two sections of the silicone tube in series through the lead to form a double-spiral shape which is mutually sleeved, bonding more than one layer of the double-spiral shape up and down, and connecting the double-spiral silicone tube in series through the lead to form a piezoresistive unit;

and overlapping the pressure-containing units and the pressure-resistance units, and packaging the pressure-containing units and the pressure-resistance units side by side between packaging films.

Technical Field

The invention relates to the field of sensors, in particular to a flexible sensing unit capable of detecting multi-level force and a manufacturing method thereof.

Background

The sensing technology is always a development direction with great challenges and potentials, and has wide development prospects in the fields of robots, medical health and the like. With the rapid development of subdivision fields such as human-computer interaction, motion health monitoring and the like, related products put forward higher requirements on the sensing unit, the sensor is required to have certain flexibility so as to be capable of being tightly attached to various non-planar surfaces of the robot, and a wide-range detectable range is required to meet the requirements of most of robot application scenes.

Since 2004, researchers have developed flexible sensing units based on piezoresistive, capacitive, piezoelectric and organic field effect transistors, but from the current research results, it can be seen that a force sensor based on a single detection principle is difficult to cover a wide range of force variations, which seriously affects the application range of the sensor in the robot field.

Disclosure of Invention

The present invention is directed to a flexible sensing unit capable of detecting multi-level forces and a method for manufacturing the same, so as to solve the above-mentioned problems in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a flexible sensing unit capable of detecting multi-level force comprises an upper packaging film, a pressure-volume unit, a piezoresistive unit and a lower packaging film; the pressure-containing unit and the pressure-resistance unit are stacked and packaged between the upper packaging film and the lower packaging film; the pressure capacity unit comprises an upper polar plate, a dielectric layer and a lower polar plate, the upper polar plate and the lower polar plate have the same structure, and the dielectric layer is arranged between the upper polar plate and the lower polar plate; the piezoresistive unit comprises a silicone tube and a liquid conductive alloy, and the liquid conductive alloy is injected into the silicone tube; the upper packaging film is connected with the upper pole plate of the pressure-capacitance unit, the lower pole plate of the pressure-capacitance unit is superposed with the upper layer of the pressure-resistance unit, and the bottom layer of the pressure-resistance unit is connected with the lower packaging film.

Preferably, the upper polar plate and the lower polar plate structurally comprise a copper foil conductive adhesive tape and a chromium sheet; the two layers of the copper foil conductive tapes are arranged side by side in an orthogonal mode, and the chromium sheets are arranged at the orthogonal positions of the two layers of the copper foil conductive tapes.

Preferably, the copper foil conductive adhesive tape is provided with an adhesive surface, the adhesive surfaces of the two layers of copper foil conductive adhesive tapes are oppositely arranged, and the chromium sheet is fixed through the adhesive surfaces.

Preferably, the dielectric layer comprises nano adhesive tapes, and more than one layer of nano adhesive tapes are mutually and orthogonally stacked in pairs.

Preferably, the liquid conductive alloy is indium gallium alloy, indium gallium tin alloy or bismuth indium tin alloy.

Preferably, the silicone tube is in a spiral shape, the two sections of silicone tubes are connected in series, and the formed spiral shape is sleeved to form a double-spiral shape.

Preferably, the piezoresistive unit is provided with more than one layer of double-spiral silicone tubes, and two adjacent layers of silicone tubes are bonded through silicone.

A flexible sensing unit manufacturing method capable of detecting multi-level force is characterized in that a copper foil conductive adhesive tape is placed in an orthogonal mode, and a chromium plate is installed at the orthogonal position to form an electrode plate; orthogonally placing the layers of the nano adhesive tapes which are placed side by side to form a dielectric layer; installing the dielectric layer between the two electrode plates to form a pressure-volume unit;

injecting liquid conductive alloy into a silicone tube, sealing two ends of the silicone tube, leading out a lead to be spiral, connecting two sections of the silicone tube in series through the lead to form a double-spiral shape which is mutually sleeved, bonding more than one layer of the double-spiral shape up and down, and connecting the double-spiral silicone tube in series through the lead to form a piezoresistive unit;

and overlapping the pressure-containing units and the pressure-resistance units, and packaging the pressure-containing units and the pressure-resistance units side by side between packaging films.

The invention has the beneficial effects that: the invention provides a flexible sensing unit capable of detecting multistage force and a manufacturing method thereof.A pressure-capacitance unit works in a range with smaller external force, a pressure-resistance unit works in a range with larger external force, and a capacitance unit and a resistance unit are mutually converted in the working process, so that the accuracy of multistage force measurement can be ensured, and the range of the measured force can be improved; according to the invention, the rigid material is cut and the array mounting structure is adopted, so that the Young modulus of the whole sensing unit is reduced, and the whole extensibility and bendability of the device are improved; the liquid conductive alloy realizes the overall high flexibility and expandability of the device and high stability and reliability under the action of stress.

Drawings

FIG. 1 is a schematic diagram of a flexible sensing unit structure;

FIG. 2 is a schematic view of a pressure-containing unit;

FIG. 3 is a schematic view of a piezoresistive cell structure;

FIG. 4 is a flow chart of the flexible sensing unit integrated package;

in the figure, 1 is an upper packaging film, 2 is a pressure volume unit, 3 is a pressure resistance unit, 4 is a lower packaging film, 5 is an upper polar plate, 6 is a dielectric layer, 7 is a lower polar plate, 8 is a silicone tube, and 9 is a silica gel.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

A flexible sensing unit capable of detecting multi-level force adopts a mode of combining pressure capacity and piezoresistive coupling force to detect multi-level large-range force, and comprises an upper packaging film, a pressure capacity unit, a piezoresistive unit and a lower packaging film as shown in figure 1.

The pressure-capacitance unit comprises an upper polar plate, a dielectric layer and a lower polar plate as shown in figure 2; the upper pole plate and the lower pole plate are identical in structure and comprise copper foil conductive adhesive tapes and chromium sheets, the copper foil conductive adhesive tapes are provided with two layers, each layer is formed by the copper foil conductive adhesive tapes which are arranged side by side at a certain distance, an adhesive surface is arranged in each copper foil conductive adhesive tape, the two layers of the copper foil conductive adhesive tapes which are arranged side by side are orthogonally arranged, the adhesive surfaces in the two layers of the copper foil conductive adhesive tapes are oppositely arranged, the chromium sheets are arranged at the orthogonal positions between the two layers of the copper foil conductive adhesive tapes, and the chromium sheets are fixedly arranged through the adhesive surfaces; the dielectric layer comprises more than one layer of nano adhesive tape for lamination, and the nano adhesive tapes of adjacent layers are orthogonally arranged; the dielectric layer is arranged between the upper polar plate and the lower polar plate and packaged to form the pressure-capacitance unit.

The piezoresistive unit is shown in fig. 3 and comprises silicone tubes and liquid conductive alloy, the liquid conductive alloy is injected into the silicone tubes to seal two ends of the silicone tubes, leads are led out of the sealed silicone tubes, the silicone tubes are arranged in a spiral shape, each layer of the piezoresistive unit comprises two silicone tubes, the two silicone tubes are connected in series through led-out strip lines and are sleeved with each other to form a double-spiral shape, the piezoresistive unit comprises more than one layer of silicone tubes forming the double-spiral shape, leads at two ends led out of each layer of the silicone tubes are respectively connected in series with leads led out of the silicone tubes of the adjacent layer, and the silicone tubes of the adjacent layer are bonded through silicone to form the piezoresistive unit; the liquid conductive alloy is indium gallium alloy, indium gallium tin alloy or bismuth indium tin alloy.

The pressure-containing unit and the pressure-resistance unit are stacked and integrally packaged between the upper packaging film and the lower packaging film.

The working principle of the flexible sensing unit capable of detecting the multistage force is as follows: when the external force acting on the flexible sensing unit is small, the electrode plates in the pressure-capacitance unit generate small displacement change, the dielectric coefficient between the upper electrode plate and the lower electrode plate is changed, and therefore the capacitance is changed, and at the moment, the flexible sensing unit works in a pressure-capacitance mode; when the external force acting on the flexible sensing unit is large, the capacitance value in the pressure-capacitance unit reaches the maximum value, the pressure-resistance unit starts to bear pressure, the silicone tube injected with the liquid conductive alloy in the pressure-resistance unit starts to be extruded and deformed, the cross-sectional area of the silicone tube is reduced at the moment, and the pressure-resistance unit is internally provided with a formula: and the output resistance of the silicone tube is increased by R ═ rho/A, and at the moment, the flexible sensing unit works in a piezoresistive mode. Wherein rho represents the resistivity of the liquid conductive alloy in the silicone tube, l represents the length of the silicone tube, and A represents the cross-sectional area of the silicone tube.

A method for manufacturing a flexible sensing unit capable of detecting multi-level force comprises the steps of manufacturing a pressure capacitance unit and a pressure resistance unit, orthogonally placing a copper foil conductive adhesive tape, and mounting a chromium plate at the orthogonal position to form an electrode plate, as shown in figure 4; the nano adhesive tape is orthogonally arranged between the layers to form a dielectric layer; installing the dielectric layer between the two electrode plates to form a pressure-volume unit;

simultaneously, after the liquid conductive alloy is injected into the silicone tube, two ends of the silicone tube are sealed, a lead is led out, the silicone tube is set to be spiral, two sections of the silicone tube are connected in series through the lead to form a double-spiral shape which is mutually sleeved, more than one layer of the double-spiral shape is vertically bonded, and the silicone tube in the double-spiral shape is connected in series through the lead to form a piezoresistive unit;

and finally, overlapping the pressure-containing units and the pressure-resistance units, and packaging the pressure-containing units and the pressure-resistance units between packaging films side by side.

Examples

In the embodiment, the width of the copper foil conductive adhesive tape is set to be about 1cm, the chromium plate is cut to be 1cm by 1cm, and the chromium plate is completely attached to an orthogonal position between the orthogonally placed copper foil conductive adhesive tapes; setting the nano adhesive tape of the dielectric layer to 4-5 layers; the silicon rubber tube forming the double-spiral shape in the piezoresistive unit is arranged into 3 layers and is bonded through silicon rubber. The pressure-capacitance unit is arranged on the upper portion, the pressure-resistance unit is arranged on the lower portion and is integrally packaged between the upper packaging film and the lower packaging film, the upper packaging film is connected with an upper pole plate of the pressure-capacitance unit, a lower pole plate of the pressure-capacitance unit and an upper layer of the pressure-resistance unit are stacked, and a bottom layer of the pressure-resistance unit is connected with the lower packaging film.

By adopting the technical scheme disclosed by the invention, the following beneficial effects are obtained:

the invention provides a flexible sensing unit capable of detecting multistage force and a manufacturing method thereof.A pressure-capacitance unit works in a range with smaller external force, a pressure-resistance unit works in a range with larger external force, and a capacitance unit and a resistance unit are mutually converted in the working process, so that the accuracy of multistage force measurement can be ensured, and the range of the measured force can be improved; according to the invention, the rigid material is cut and the array mounting structure is adopted, so that the Young modulus of the whole sensing unit is reduced, and the whole extensibility and bendability of the device are improved; the liquid conductive alloy realizes the overall high flexibility and expandability of the device and high stability and reliability under the action of stress.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements should also be considered within the scope of the present invention.