Customizable electronic skin sensor and preparation method thereof

Abstract

The invention belongs to the technical field of sensing, and relates to a customizable electronic skin sensor and a preparation method thereof. The structure and the shape of the sensor can be customized according to specific application requirements. The sensor is mainly composed of an electret polymer film, a conductive material and a stretchable packaging material, so that the sensor is endowed with excellent sensing characteristics and stretchability and has waterproof and sweat-proof performance. Compared with the prior art, the sensor is simple in manufacturing process, regular and adjustable in structure, high in sensitivity, fast in response, high in environmental adaptability and wide in application.

Description

Technical Field

[0001] The present invention belongs to the field of sensor technology, and in particular relates to a customizable electronic skin sensor and a preparation method thereof. Background Art

[0002] With the rapid development of wearable electronic devices and flexible electronic technology, electronic skin sensors, as flexible sensors that simulate the functions of human skin, are increasingly used in health monitoring, human-computer interaction, and intelligent robots. Electronic skin sensors need to have high flexibility, high sensitivity, and structural stability to ensure their reliability and durability in various environments. However, traditional electronic skin sensor preparation methods often have problems such as low preparation efficiency, irregular structure, and unstable bonding quality, which limit the large-scale production and application of electronic skin sensors.

[0003] Chinese patent CN115219076A discloses a high-performance electronic skin tactile sensor based on liquid metal and a method for preparing the same. This patent develops a new type of flexible pressure sensor by using liquid metal. This sensor uses two sensing methods, capacitive and resistive, and has higher sensitivity, faster response time and stronger durability than traditional methods. However, this method has the problems of low processing efficiency and complex preparation process, especially when preparing electronic skin sensors with large areas or complex structures, involving multiple materials and complex processing steps. In addition, the high cost of femtosecond laser equipment limits its application in large-scale production. Chinese patent CN107778480A provides a flexible electronic skin sensor and a method for preparing the same, including a number of pressure sensing units, which are composed of two flexible and retractable ultra-thin PDMS films, two electrodes respectively attached between the two ultra-thin PDMS films, and a composite pressure sensing film arranged between the two electrodes. The sensor uses a composite pressure sensing membrane with a hollow structure, which has outstanding elasticity and ultra-low elastic modulus, so that the pressure sensing unit can effectively amplify and convert various external stimuli and can be used to monitor human body signals. However, the manufacturing process of the sensor is also relatively complex and the cost is high, which is not conducive to large-scale production and application. Summary of the invention

[0004] The purpose of the present invention is to provide a customizable electronic skin sensor and a preparation method thereof in order to overcome the problems existing in the above-mentioned prior art. The sensor has a simple manufacturing process, a regular and adjustable structure, high sensitivity, fast response, strong environmental adaptability, and wide application.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention provides a customizable electronic skin sensor, comprising a sensitive layer, an electrode layer and a packaging layer arranged in sequence from the inside to the outside.

[0007] The electrode layer is provided with an electrode lead wire connected to an external load circuit.

[0008] Furthermore, the sensitive layer is made of electret polymer film material; the electrode layer is made of conductive material, which is conductive metal or conductive oxide, for example, the conductive metal is silver nanowire, and the conductive oxide is zinc oxide or indium tin oxide; the encapsulation layer is made of human silicone or Ecoflex silicone.

[0009] In another aspect, the present invention also provides a customizable mold for preparing an electronic skin sensor as described above, the mold comprising: an upper clamping plate, a lower clamping plate, a support layer, and a plurality of support rollers;

[0010] A first cavity for accommodating the electret polymer film is formed between the upper clamping plate and the supporting layer.

[0011] A second cavity for accommodating the electret polymer film is formed between the lower clamping plate and the supporting layer.

[0012] The upper clamping plate and the lower clamping plate are both provided with a plurality of thermal bonding gaps, and the thermal bonding gaps are adapted to the supporting rollers.

[0013] Furthermore, the support layer is composed of a plurality of support partitions, and the width of each support partition is equal to the width of the clamping plates between adjacent thermal bonding gaps; the length of the support layer is greater than the lengths of the upper clamping plates and the lower clamping plates.

[0014] Furthermore, the sizes and shapes of the upper clamping plate, the lower clamping plate and the supporting layer of the mold are adjusted according to the sizes and shapes required by the electronic skin sensor.

[0015] In a third aspect, the present invention also provides a method for preparing a customizable electronic skin sensor using the above mold, comprising the following steps:

[0016] S1, performing polarization treatment on two electret polymer films respectively to obtain two electret polymer films with positive and negative charges distributed on the surface respectively;

[0017] S2, placing the two electret polymer films obtained in step S1 with their positive and negative polarized surfaces facing each other in the first cavity and the second cavity of the mold respectively; closing the molds; placing a support roller at the thermal bonding gap, heating the gap to bond the gap; after the thermal bonding is completed, demolding to obtain an electret polymer film, which serves as a sensitive layer and has holes formed inside;

[0018] S3, coating an electrode layer on the outside of the sensitive layer, and leading electrode leads from the electrode layer to form a hole / sensitive layer / electrode layer;

[0019] S4, setting a packaging layer outside the electrode layer to obtain an electronic skin sensor.

[0020] Furthermore, in step S1, the polarization treatment is carried out by corona polarization, ion implantation or electron beam implantation, so that charges are distributed on one surface of the electret polymer film.

[0021] Furthermore, in step S4, the encapsulation layer is disposed outside the electrode layer by dip coating, pulling, coating or spin coating.

[0022] The present invention also provides another method for preparing a customizable electronic skin sensor using the above mold, comprising the following steps:

[0023] S1, placing two electret polymer films in the first cavity and the second cavity of the mold respectively; closing the mold; placing a support roller at the thermal bonding gap, heating to bond the thermal bonding gap; after the thermal bonding is completed, demolding to obtain an electret polymer film with holes formed inside, i.e., hole / electret polymer film;

[0024] S2, coating an electrode layer on the outside of the electret polymer film obtained in step S1, and leading electrode leads from the electrode layer to form holes / electret polymer film / electrode layer;

[0025] S3, setting a packaging layer outside the electrode layer to form a hole / electret polymer film / electrode layer / packaging layer;

[0026] S4, performing polarization treatment on the holes / electret polymer film / electrode layer / encapsulation layer obtained in step S3, so that charges are distributed on the inner surface of the holes of the electret polymer film, thereby obtaining an electronic skin sensor.

[0027] Furthermore, in step S3, the encapsulation layer is disposed outside the electrode layer by dip coating, pulling, coating or spin coating.

[0028] Furthermore, in step S4, the polarization treatment is to use contact polarization to inject bipolar charges into the inner surface of the pores of the electret polymer film.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) Structural adjustability: The sensor of the present invention uses a customizable mold during the preparation process, so that the structure and shape of the sensor can be customized according to specific application requirements. The design flexibility of the mold allows the geometric parameters of the sensor to be precisely adjusted during the production process, including but not limited to size, thickness, shape and surface texture; in addition, thermal bonding is a technology that combines two or more layers of thin films through a high-temperature melting process, and the bonding effect can be optimized by controlling parameters such as temperature, pressure, time and heating rate. The adjustability of the geometric parameters and thermal bonding process parameters of this sensor not only improves the adaptability of the sensor, enabling it to meet a variety of application scenarios such as medical equipment, industrial automation and environmental monitoring, but also greatly enhances its performance in specific applications. For example, in precision measurement applications, the sensor can be customized according to the size and shape of the measured object to achieve optimal fit and sensitivity. In addition, this structural adjustability also provides broad space for future product development and innovation, allowing the sensor of the present invention to quickly respond to market changes and technological advances.

[0031] (2) Strong environmental adaptability: The process flow of the present invention is simple, and the sensor is mainly composed of an electret polymer film and a stretchable packaging material. The selection of these materials not only gives the sensor excellent sensing characteristics and stretchability, but also has waterproof and sweat-proof properties. In harsh environments such as humidity, heat or cold, the sensor of the present invention can still maintain high sensitivity and measurement accuracy.

[0032] (3) High sensitivity and charge storage stability: The present invention improves the detection sensitivity of the sensor by optimizing the preparation method of the sensor, which can sense extremely small pressure changes and is suitable for monitoring weak physiological signals of the human body. In addition, the flexible electret polymer film of the present invention not only gives the sensor high sensitivity, but also brings excellent charge storage stability, which is outstanding among similar charging films. This feature enables the sensor to have a longer service life when used as robot skin or in applications for monitoring human physiological signals.

[0033] (4) Adjustable stretch and strain sensing performance: The sensor can respond quickly to changes in external pressure in a short period of time, which is of great significance for dynamic tactile perception, thereby meeting the specific requirements for sensor performance in different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of the mold used in Examples 1-2 of the present invention, wherein (a) is a side view, (b) is a front view, and (c) is a top view;

[0035] Figure 2 This is a schematic diagram of the structure of the electronic skin sensor of Embodiment 1-2 of the present invention;

[0036] Figure 3 This is a SEM image of the electronic skin sensor of Example 1 of the present invention;

[0037] Figure 4 This is a SEM image of the electronic skin sensor of Example 2 of the present invention;

[0038] Figure 5 Schematic diagram of the structure of the mold used in Examples 3-4 of the present invention, wherein (a) is a side view, (b) is a front view, and (c) is a top view;

[0039] Figure 6 This is a schematic diagram of the structure of the electronic skin sensor of Embodiment 3-4 of the present invention;

[0040] Figure 7 Schematic diagram of the structure of the mold used in Examples 5-6 of the present invention, wherein (a) is a side view, (b) is a front view, and (c) is a top view;

[0041] Figure 8 This is a schematic diagram of the structure of the electronic skin sensor of Embodiment 5-6 of the present invention;

[0042] Fig. 9 This is a normalized output voltage diagram of the electronic skin sensor at different temperatures according to Example 1 of the present invention;

[0043] Fig.10 This is a sensitivity test result diagram of the electronic skin sensor according to Example 1 of the present invention.

[0044] Description of the markings in the figure:

[0045] 1-upper clamp, 2-support layer, 3-thermal bonding gap, 4-lower clamp, 5-support roller, 6-upper packaging layer, 7-upper electrode, 8-upper film, 9-lower film, 10-lower electrode, 11-lower packaging layer, 12-hole layer, 13-upper electrode lead, 14-lower electrode lead. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0047] The present invention provides a customizable electronic skin sensor, comprising a sensitive layer, an electrode layer and a packaging layer arranged in sequence from the inside to the outside, wherein the electrode layer is provided with an electrode lead wire connected to an external load circuit. The sensitive layer is made of an electret polymer film material; the electrode layer is made of a conductive material, which is a conductive metal or a conductive oxide, for example, the conductive metal is silver nanowire, and the conductive oxide is zinc oxide or indium tin oxide; the packaging layer is made of human silicone or Ecoflex silicone.

[0048] The above-mentioned customizable mold for preparing electronic skin sensors includes: an upper clamping plate, a lower clamping plate, a support layer and a plurality of support rollers; a first cavity for accommodating an electret polymer film is formed between the upper clamping plate and the support layer, a second cavity for accommodating an electret polymer film is formed between the lower clamping plate and the support layer, and a plurality of thermal bonding gaps are provided on the upper clamping plate and the lower clamping plate, and the thermal bonding gaps are adapted to the support rollers. The support layer is composed of a plurality of support partitions, and the width of each support partition is equal to the width of the clamping plate between adjacent thermal bonding gaps; the length of the support layer is greater than the length of the upper clamping plate and the lower clamping plate.

[0049] In some specific embodiments, the sizes and shapes of the upper clamping plate, the lower clamping plate and the supporting layer of the mold are adjusted according to the required size and shape of the electronic skin sensor.

[0050] The electronic skin sensor is manufactured by the following method using the above mold:

[0051] S1, polarizing the two electret polymer films respectively by corona polarization, ion implantation or electron beam implantation, so that charges are distributed on one surface of the electret polymer film, thereby obtaining two electret polymer films with positive and negative charges distributed on the surface respectively;

[0052] S2, placing the positive and negative polarized surfaces of the two electret polymer films obtained in step S1 opposite to each other in the first cavity and the second cavity of the mold respectively; closing the mold (aligning the upper clamping plate, the lower clamping plate, and the thermal bonding gap provided thereon); placing a support roller at the thermal bonding gap to prevent damage to the electret polymer film during the bonding process, heating with an electric soldering iron to bond the thermal bonding gap, and setting the bonding temperature according to the specific characteristics of the electret polymer film material; after the thermal bonding is completed, demoulding (removing the support roller, the upper clamping plate, the lower clamping plate in turn, and finally removing the support layer) to obtain an electret polymer film, which serves as a sensitive layer and has holes formed inside;

[0053] S3, coating an electrode layer on the outside of the sensitive layer, and leading electrode leads from the electrode layer to form a hole / sensitive layer / electrode layer;

[0054] S4, disposing a packaging layer outside the electrode layer by dip coating, coating or spin coating to obtain an electronic skin sensor.

[0055] The above mold can also be used to make an electronic skin sensor by the following method:

[0056] S1, placing two electret polymer films in the first cavity and the second cavity of the mold respectively; closing the mold (aligning the upper clamping plate, the lower clamping plate, and the thermal bonding gap set thereon); placing a support roller at the thermal bonding gap, heating it with an electric soldering iron, so that the thermal bonding gap is bonded, and the bonding temperature is set according to the specific characteristics of the electret polymer film material; after the thermal bonding is completed, demolding (removing the support roller, the upper clamping plate, the lower clamping plate in turn, and finally removing the support layer) to obtain an electret polymer film, the inner side of which has holes, that is, holes / electret polymer film;

[0057] S2, coating an electrode layer on the outside of the electret polymer film obtained in step S1, and leading electrode leads from the electrode layer to form holes / electret polymer film / electrode layer;

[0058] S3, disposing an encapsulation layer outside the electrode layer by dip coating, coating or spin coating to form a hole / electret polymer film / electrode layer / encapsulation layer;

[0059] S4, polarizing the holes / electret polymer film / electrode layer / encapsulation layer obtained in step S3: using contact polarization to inject bipolar charges into the inner surface of the holes of the electret polymer film, so that the inner surface of the holes of the electret polymer film is distributed with charges, thereby obtaining an electronic skin sensor.

[0060] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available. For example, the transparent PLA film used in the examples of the present invention was purchased from Shenzhen Guanghua Weiye Co., Ltd., with a density of 1.24 g / cm 3 , with a transparency of 80%.

[0061] Example 1

[0062] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0063] (1) Select two transparent PLA films with a thickness of 15 μm;

[0064] (2) The two PLA films were subjected to positive / negative corona polarization respectively using a scanning corona polarization device, with a polarization voltage of ±10 kV and a time of 5 min;

[0065] (3) After the positive / negatively polarized PLA film was placed in the laboratory for 5 days, Figure 1 In the mold shown (the major axis of each ellipse of the support layer is 6 mm), a soldering iron is used for thermal bonding. Specifically, one of the polarized PLA films is placed between the upper clamp and the support layer, and the other polarized PLA film is placed between the lower clamp and the support layer, with the charged surfaces of the two films facing each other. Then, the upper clamp and the lower clamp are aligned, and the support roller is placed at the thermal bonding gap to ensure that the polarized PLA film is not easily damaged during bonding. The two polarized PLA films are bonded at the thermal bonding gap with a soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamp and the lower clamp are removed, and finally the support layers between the two polarized PLA films are removed in turn. The composite polarized PLA film containing an elliptical microporous structure is prepared, as shown in FIG. Figure 2 , Figure 3 shown.

[0066] (4) coating the upper and lower surfaces of the composite polarized PLA film obtained in step (3) with nano silver wires, and leading upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0067] (5) Select transparent Ecoflex silica gel, and use the dip-coating method to encapsulate the upper and lower surfaces of the composite polarized PLA film coated with nanosilver wires obtained in step (4) to obtain a high-regularity electronic skin sensor, such as Figure 3 shown.

[0068] The electronic skin sensor obtained in this embodiment was tested as follows:

[0069] (1) Output voltage at different temperatures

[0070] Test method:

[0071] Equipment preparation: Select the sensor or electronic device to be tested and ensure it is in normal working condition before testing.

[0072] Environmental simulation: Use an environmental simulation chamber to simulate hot or cold environmental conditions. The chamber should have temperature control function and can be accurately adjusted to the required test temperature.

[0073] Connecting equipment: Connect the sensor or electronic device to the Keithley 6514 data logger to ensure that the data acquisition system can record the output voltage in real time.

[0074] Preheating / Cooling: Before starting the test, place the device in an environmental simulation chamber to preheat or cool to the required test temperature to ensure that the device reaches thermal equilibrium.

[0075] Data collection: After the device reaches thermal equilibrium, data collection begins. Record the output voltage of the device at different temperatures and calculate the normalized output voltage.

[0076] Test temperature: -20℃, 30℃, 60℃, 90℃.

[0077] Warm-up / Cool-down time: At least 30 minutes to ensure the equipment reaches thermal equilibrium.

[0078] Test period: record data for at least 1 hour at each temperature.

[0079] Normalized reference: Select the output voltage of a sensor or electronic device at room temperature (such as 25°C) as the reference.

[0080] The test results are as follows Fig. 9 As shown, the variation trend of the normalized output voltage of the electronic skin sensor of this embodiment at different temperatures can be clearly observed: at a relatively high temperature of 60°C, the average value of the normalized output voltage decreases slightly. Although the performance of the sensor at high temperature is reduced, the reduction is not large; at a low temperature of -20°C, the average value of the normalized output voltage increases slightly, indicating that the performance of the sensor at low temperatures is improved. Fig. 9 The error bars in the graph indicate the fluctuation range of the test results at each temperature. Fig. 9 The results show that the electronic skin sensor of the present invention has strong environmental adaptability. In harsh environments such as hot or cold, the sensor of the present invention can still maintain high sensitivity and measurement accuracy.

[0081] (2) Sensitivity test

[0082] Test method:

[0083] Equipment preparation: Select the sensor to be tested and make sure it is in normal working condition.

[0084] Environmental Control: Tests are performed in a constant temperature environment to eliminate the effects of temperature changes on test results.

[0085] Connecting Equipment: Connect the sensor to a Keithley 6514 electrometer to ensure that the output of the sensor can be accurately recorded.

[0086] Apply pressure: Use a pressure test device to gradually increase the pressure to the sensor and record the output voltage at each pressure point.

[0087] Data logging: After stabilization at each pressure point, record the output voltage of the sensor.

[0088] Test conditions:

[0089] Test environment: constant temperature room, the temperature is controlled at 25℃.

[0090] Pressure range: from 0kPa to 4.0kPa, in increments of 0.5kPa.

[0091] Stabilization Time: After each pressure point is applied, wait at least 30 seconds to ensure the sensor output stabilizes.

[0092] Test cycle: record data at least 3 times for each pressure point and take the average value to reduce error.

[0093] Calculating Sensitivity: Sensitivity is defined as the ratio of the change in output voltage to the change in input pressure.

[0094] Sensitivity test results are as follows Fig.10 As shown, the changes in sensor output voltage under different pressures are clearly demonstrated. Fig.10 The curves in represent the response of the electronic skin sensor of this embodiment to pressure changes under different initial pressures P0 (0.5kPa, 1.5kPa, 4.0kPa). It can be observed that as the initial pressure increases, the output voltage of the sensor also increases, showing the linear response characteristics of the sensor, indicating that the electronic skin sensor of the present invention has high sensitivity, can sense small pressure changes, and quickly respond to changes in external pressure in a short time, which is of great significance for dynamic tactile perception, thereby meeting the specific requirements for sensor performance in different application scenarios.

[0095] Example 2

[0096] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0097] (1) Select two transparent PLA films with a thickness of 15 μm;

[0098] (2) Figure 1 In the mold shown (the major axis of each ellipse of the support layer is 6 mm), an electric soldering iron is used to thermally bond two transparent PLA films. Specifically, one PLA film is placed between the upper clamp and the support layer, and the other PLA film is placed between the lower clamp and the support layer. Then, the upper clamp and the lower clamp are aligned, and the support roller is placed at the thermal bonding gap to ensure that the PLA film is not easily damaged during bonding. The two PLA films are bonded at the thermal bonding gap with an electric soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamp and the lower clamp are removed, and finally the support layer between the two layers of PLA films is removed in turn. The composite PLA film containing an elliptical microporous structure is prepared, as shown in FIG. Figure 2 , Figure 4 shown.

[0099] (3) coating the upper and lower surfaces of the composite PLA film obtained in step (2) with nano silver wires, and extending upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0100] (4) Selecting transparent Ecoflex silica gel, and encapsulating the upper and lower surfaces of the composite PLA film coated with nano silver wires obtained in step (3) by dip coating and pulling method;

[0101] (5) Using a contact polarization device, the encapsulated composite structure PLA film obtained in step (4) is polarized at a polarization voltage of 2 kV for 2 min to obtain a high-regularity electronic skin sensor, such as Figure 4 shown.

[0102] Example 3

[0103] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0104] (1) Select two transparent PLA films with a thickness of 20 μm;

[0105] (2) The two PLA films were subjected to positive / negative corona polarization respectively using a scanning corona polarization device, with a polarization voltage of ±10 kV and a time of 5 min;

[0106] (3) After the positive / negatively polarized PLA film was placed in the laboratory for 5 days, Figure 5 In the mold shown, a soldering iron is used for thermal bonding. Specifically, one of the polarized PLA films is placed between the upper clamp and the support layer, and the other polarized PLA film is placed between the lower clamp and the support layer, with the charging surfaces of the two films facing each other. Then, the upper clamp and the lower clamp are aligned, and the support roller is placed at the thermal bonding gap to ensure that the polarized PLA film is not easily damaged during bonding. The two polarized PLA films are bonded at the thermal bonding gap with a soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamp and the lower clamp are removed, and finally the support layer between the two polarized PLA films is removed in turn, and the composite polarized PLA film containing a microporous structure is prepared.

[0107] (4) coating the upper and lower surfaces of the composite polarized PLA film obtained in step (3) with nano silver wires, and leading upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0108] (5) Select transparent Ecoflex silica gel, and use the dip-coating method to encapsulate the upper and lower surfaces of the composite polarized PLA film coated with nanosilver wires obtained in step (4) to obtain a high-regularity electronic skin sensor, such as Figure 6 shown.

[0109] Example 4

[0110] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0111] (1) Select two transparent PLA films with a thickness of 20 μm;

[0112] (2) Figure 5 In the mold shown, an electric soldering iron is used to thermally bond two transparent PLA films. Specifically, one PLA film is placed between the upper clamping plate and the support layer, and the other PLA film is placed between the lower clamping plate and the support layer. Then, the upper clamping plate and the lower clamping plate are aligned, and the support roller is placed at the thermal bonding gap to ensure that the PLA film is not easily damaged during bonding. The two PLA films are bonded at the thermal bonding gap with an electric soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamping plate and the lower clamping plate are removed, and finally the support layer between the two PLA films is removed in turn, and the composite PLA film containing a microporous structure is prepared.

[0113] (3) coating the upper and lower surfaces of the composite PLA film obtained in step (2) with nano silver wires, and extending upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0114] (4) Selecting transparent Ecoflex silica gel, and encapsulating the upper and lower surfaces of the composite PLA film coated with nano silver wires obtained in step (3) by dip coating and pulling method;

[0115] (5) Using a contact polarization device, the encapsulated composite structure PLA film obtained in step (4) is polarized at a polarization voltage of 2 kV for 2 min to obtain a high-regularity electronic skin sensor, such as Figure 6 shown.

[0116] Example 5

[0117] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0118] (1) Select two transparent PLA films with a thickness of 10 μm;

[0119] (2) The two PLA films were subjected to positive / negative corona polarization respectively using a scanning corona polarization device, with a polarization voltage of ±10 kV and a time of 5 min;

[0120] (3) After the positive / negatively polarized PLA film was placed in the laboratory for 5 days, Figure 7In the mold shown, a soldering iron is used for thermal bonding. Specifically, one of the polarized PLA films is placed between the upper clamp and the support layer, and the other polarized PLA film is placed between the lower clamp and the support layer, with the charging surfaces of the two films facing each other. Then, the upper clamp and the lower clamp are aligned, and the support roller is placed at the thermal bonding gap to ensure that the polarized PLA film is not easily damaged during bonding. The two polarized PLA films are bonded at the thermal bonding gap with a soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamp and the lower clamp are removed, and finally the support layer between the two polarized PLA films is removed in turn, and the composite polarized PLA film containing a microporous structure is prepared.

[0121] (4) coating the upper and lower surfaces of the composite polarized PLA film obtained in step (3) with nano silver wires, and leading upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0122] (5) Select transparent Ecoflex silica gel, and use the dip-coating method to encapsulate the upper and lower surfaces of the composite polarized PLA film coated with nanosilver wires obtained in step (4) to obtain a high-regularity electronic skin sensor, such as Figure 8 shown.

[0123] Example 6

[0124] This embodiment provides an electronic skin sensor, and the preparation method is as follows:

[0125] (1) Select two transparent PLA films with a thickness of 10 μm;

[0126] (2) Figure 7 In the mold shown, an electric soldering iron is used to thermally bond two transparent PLA films. Specifically, one PLA film is placed between the upper clamping plate and the support layer, and the other PLA film is placed between the lower clamping plate and the support layer. Then, the upper clamping plate and the lower clamping plate are aligned, and the support roller is placed at the thermal bonding gap to ensure that the PLA film is not easily damaged during bonding. The two PLA films are bonded at the thermal bonding gap with an electric soldering iron, and the bonding temperature is 150°C. After bonding, the support roller is removed, and then the upper clamping plate and the lower clamping plate are removed, and finally the support layer between the two PLA films is removed in turn, and the composite PLA film containing a microporous structure is prepared.

[0127] (3) coating the upper and lower surfaces of the composite PLA film obtained in step (2) with nano silver wires, and extending upper and lower electrode leads from the upper and lower surfaces of the film, respectively;

[0128] (4) Selecting transparent Ecoflex silica gel, and encapsulating the upper and lower surfaces of the composite PLA film coated with nano silver wires obtained in step (3) by dip coating and pulling method;

[0129] (5) Using a contact polarization device, the encapsulated composite structure PLA film obtained in step (4) is polarized at a polarization voltage of 2 kV for 2 min to obtain a high-regularity electronic skin sensor, such as Figure 8 shown.

[0130] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A customizable electronic skin sensor, characterized in that: It includes a sensitive layer, an electrode layer and a packaging layer arranged in sequence from the inside to the outside. The electrode layer is provided with an electrode lead wire connected to an external load circuit.

2. A customizable electronic skin sensor according to claim 1, characterized in that: The sensitive layer is made of electret polymer film material; The electrode layer is made of conductive material, such as conductive metal or conductive oxide; The encapsulation layer is made of human silicone or Ecoflex silicone.

3. A customizable electronic skin sensor preparation mold as claimed in claim 1 or 2, characterized in that: The mold comprises: an upper clamping plate, a lower clamping plate, a support layer and a plurality of support rollers; A first cavity for accommodating the electret polymer film is formed between the upper clamping plate and the supporting layer. A second cavity for accommodating the electret polymer film is formed between the lower clamping plate and the supporting layer. The upper clamping plate and the lower clamping plate are both provided with a plurality of thermal bonding gaps, and the thermal bonding gaps are adapted to the supporting rollers.

4. A customizable electronic skin sensor preparation mold according to claim 3, characterized in that: The support layer is composed of a plurality of support partitions, and the width of each support partition is equal to the width of the sandwich panels between adjacent thermal bonding gaps; The length of the supporting layer is greater than the lengths of the upper clamping plate and the lower clamping plate.

5. A customizable electronic skin sensor preparation mold according to claim 3, characterized in that: The sizes and shapes of the upper clamping plate, the lower clamping plate and the supporting layer of the mold are adjusted according to the required size and shape of the electronic skin sensor.

6. A method for preparing a customizable electronic skin sensor using the mold according to claim 3, characterized in that: The steps include: S1, performing polarization treatment on two electret polymer films respectively to obtain two electret polymer films with positive and negative charges distributed on the surface respectively; S2, placing the two electret polymer films obtained in step S1 with their positive and negative polarized surfaces facing each other in the first cavity and the second cavity of the mold respectively; closing the mold; placing a support roller at the thermal bonding gap, and heating the thermal bonding gap to bond; After the thermal bonding is completed, the mold is released to obtain an electret polymer film, which serves as a sensitive layer and has holes formed on the inside; S3, coating an electrode layer on the outside of the sensitive layer, and leading electrode leads from the electrode layer to form a hole / electret polymer film / electrode layer; S4, setting a packaging layer outside the electrode layer to obtain an electronic skin sensor.

7. A method for preparing a customizable electronic skin sensor according to claim 6, characterized in that: In step S1, the polarization treatment is carried out by corona polarization, ion implantation or electron beam implantation, so that charges are distributed on one surface of the electret polymer film.

8. A method for preparing a customizable electronic skin sensor using the mold according to claim 3, characterized in that: The steps include: S1, placing two electret polymer films in the first cavity and the second cavity of the mold respectively; closing the mold; placing a support roller at the thermal bonding gap, and heating to bond the thermal bonding gap; After the thermal bonding is completed, the mold is released to obtain an electret polymer film with holes formed on the inner side thereof, i.e., a hole / electret polymer film; S2, coating an electrode layer on the outside of the electret polymer film obtained in step S1, and leading electrode leads from the electrode layer to form holes / electret polymer film / electrode layer; S3, providing an encapsulation layer outside the electrode layer to form a hole / electret polymer film / electrode layer / encapsulation layer; S4, performing polarization treatment on the holes / electret polymer film / electrode layer / encapsulation layer obtained in step S3, so that charges are distributed on the inner surface of the holes of the electret polymer film, thereby obtaining an electronic skin sensor.

9. A method for preparing a customizable electronic skin sensor according to claim 8, characterized in that: In step S4, the polarization treatment is to use contact polarization to inject bipolar charges into the inner surface of the pores of the electret polymer film.

10. A method for preparing a customizable electronic skin sensor according to claim 6 or 8, characterized in that: The encapsulation layer is arranged outside the electrode layer by means of dipping, pulling, coating or spin coating.

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