Triboresistive touch sensor composition and triboresistive touch sensor using same

Abstract

The present invention relates to a triboresistive touch sensor composition and a triboresistive touch sensor using same. A triboresistive touch sensor composition according to an embodiment of the present invention includes polyvinyl chloride (PVC) and butyl benzoate (BB). The weight ratio of PVC and BB may be 1: 1.5 to 1: 2.5.

Description

Capacitive touch sensor composition and capacitive touch sensor using the same

[0001] The present invention relates to a capacitive touch sensor composition and a capacitive touch sensor using the same.

[0002] This invention is the result of the project 'Development of Plasticized Polymer-Based Dielectric and Ion Conductors and Application to Next-Generation Organic Electronic Devices Using 3D Printing', conducted with funding from the Ministry of Science and ICT and support from the National Research Foundation of Korea in 2024 (RS-2024-00348475).

[0003] Capacitive touch sensors are a technology that detects contact with human fingers or objects and converts it into an electrical signal, playing an important role in various fields such as wearable devices, portable electronic devices, human-machine interfaces, and soft robots. These touch sensors have been developed in various ways, including capacitive, resistive, and pressure types, and each method exhibits differentiated performance in terms of transparency, flexibility, and sensitivity.

[0004] Capacitive touch sensors determine location by utilizing changes in static electricity and resistance upon touch detection, exhibiting characteristics particularly suitable for flexible electronic devices or devices requiring deformation. This technology is attracting attention as a next-generation touch sensor due to its advantages of combining flexibility and durability while consuming little power.

[0005] Conventional capacitive and resistive touch sensors exhibit limitations in flexibility and transparency. In the case of capacitive touch sensors, stretchability is restricted due to fixed electrode arrays and complex multilayer structures, making it difficult to adapt to irregular surfaces. Additionally, existing resistive touch sensors may experience performance degradation upon repeated deformation or suffer from low transparency, which can lead to integration issues with displays.

[0006] In particular, conventional touch sensors require an external power source, resulting in poor energy efficiency, and the mechanical properties of the sensor materials deteriorate, leading to reduced reliability during long-term use. These issues act as limiting factors for the development of next-generation flexible electronic devices and wearable devices.

[0007] A relevant prior art document is Japanese Registered Patent Publication No. 6374610.

[0008] The present invention aims to provide a capacitive touch sensor composition having excellent position sensing performance and a capacitive touch sensor using the same.

[0009] In addition, the present invention has high elasticity and transparency.

[0010] In addition, the present invention has high durability.

[0011] A capacitive touch sensor composition according to an embodiment of the present invention comprises poly vinyl chloride (PVC) and butyl benzoate (BB).

[0012] The weight ratio of the above PVC and BB may be 1:1.5 to 1:2.5.

[0013]

[0014] A method for manufacturing an electrostatic resistance touch sensor layer according to an embodiment of the present invention comprises the steps of: dissolving polyvinyl chloride (PVC) in a solvent to prepare a PVC solution; adding butyl benzoate (BB) to the PVC solution to prepare a mixture; and removing the solvent from the mixture.

[0015] In the step of preparing the above mixture, the weight ratio of PVC and BB may be 1:1.5 to 1:2.5.

[0016] The above solvent may be tetrahydrofuran (THF).

[0017]

[0018] A capacitive touch sensor according to an embodiment of the present invention comprises a capacitive touch sensor layer and an electrode disposed at the edge of the capacitive touch sensor layer.

[0019] The above-mentioned capacitive touch sensor layer comprises Poly vinyl chloride (PVC) and Butyl benzoate (BB).

[0020] The weight ratio of the above PVC and BB may be 1:1.5 to 1:2.5.

[0021] A capacitive touch sensor composition according to an embodiment of the present invention and a capacitive touch sensor using the same have excellent position sensing performance.

[0022] In addition, the present invention has high elasticity and transparency.

[0023] In addition, the present invention has high durability.

[0024] FIG. 1 is a flowchart of a method for manufacturing a capacitive touch sensor layer according to an embodiment of the present invention.

[0025] Figure 2 is a conceptual diagram of a triboelectric nanogenerator fabricated for analyzing output voltage characteristics.

[0026] Figure 3 shows the result of measuring the output voltage of the triboelectric nanogenerator.

[0027] Figure 4 shows the results of measuring the power density of the triboelectric nanogenerator.

[0028] Figure 5 shows the result of measuring the dielectric constant of the capacitive touch sensor layer.

[0029] Figure 6 shows the result of measuring the surface potential of the electrostatic touch sensor layer.

[0030] Figure 7 is a one-dimensional capacitive touch sensor, (a) before stretching, and (b) after stretching by 50%.

[0031] Figure 8 is a two-dimensional capacitive touch sensor. (a) is a photograph of an actual capacitive touch sensor, and (b) is a conceptual diagram with coordinates indicated for explanation.

[0032] Figure 9 shows the result of measuring the output current according to the contact position of the electrostatic resistance touch sensor (1D-TPS) of the present invention.

[0033] Figure 10 shows the output current measured in Figure 9 calculated using Equation 1.

[0034] Figure 11 is the result of measuring the output current according to the contact position of the electrostatic resistance touch sensor (2D-TPS) of the present invention.

[0035] Figure 12 shows the output current measured in Figure 11 calculated using Equation 2.

[0036] Figure 13 shows the actual contact position and the position calculated in Figure 12 in comparison.

[0037] The drawing symbols are as follows.

[0038] 100: Capacitive touch sensor layer, 200: ITO-PET electrode, 300: Acrylic substrate, 400: Nylon, 500: Al electrode

[0039] Hereinafter, preferred embodiments of the present invention are described as follows with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

[0040]

[0041] A capacitive touch sensor composition according to an embodiment of the present invention comprises poly vinyl chloride (PVC) and butyl benzoate (BB).

[0042]

[0043] The above-mentioned Polyvinyl Chloride (PVC) is a synthetic plastic polymer utilized in various industrial fields. PVC is lightweight, highly durable, chemically stable, and inexpensive. The PVC possesses high elasticity and, when mixed with a plasticizer, provides an elongation rate of over 1714%, making it suitable for flexible and deformable electronic devices. Furthermore, it has high resistance, and by adding a plasticizer to function as a dielectric, it can maximize triboelectric generation in triboelectric nanogenerators. In this invention, the PVC, combined with a plasticizer, exhibits optimized elasticity, transparency, and electrical properties as a touch sensor composition.

[0044]

[0045] The above butyl benzoate (BB) is an ester compound, a substance formed by the combination of benzoic acid and butanol. When mixed with PVC, the BB forms a very flexible gel, providing an elongation rate of 1714% or more. In addition, it contains alkyl groups, which increase the dielectric constant of the PVC gel and increase triboelectronegativity.

[0046]

[0047] In one embodiment, the weight ratio of the PVC and BB may be 1:1.5 to 1:2.5. If the BB content is low, elasticity and flexibility decrease, and the dielectric constant decreases, which may result in a lower power density. Conversely, if the BB content is high, leakage current occurs, and charge is discharged without accumulating on the PVC gel surface, thereby degrading output performance.

[0048]

[0049] A method for manufacturing an electrostatic resistance touch sensor layer according to an embodiment of the present invention comprises the steps of: dissolving polyvinyl chloride (PVC) in a solvent to prepare a PVC solution; adding butyl benzoate (BB) to the PVC solution to prepare a mixture; and removing the solvent from the mixture.

[0050] In the step of preparing the above PVC solution, the solvent is not particularly limited as long as it dissolves PVC, and preferably, it may be Tetrahydrofuran (THF). A sufficient amount of THF to dissolve PVC may be used. This step can be performed by stirring with a stirrer at room temperature.

[0051] The step of preparing a mixture by adding butyl benzoate (BB) to the above PVC solution can be performed by adding BB to the PVC solution in which PVC is dissolved and stirring with a stirrer. In this step, the weight ratio of PVC and BB may be 1:1.5 to 1:2.5.

[0052] The step of removing the solvent from the above mixture can be performed by evaporating the solvent at a constant temperature (room temperature in one embodiment) after molding the mixture into a desired shape.

[0053] The capacitive touch sensor layer manufactured in this way is in the form of a gel, has a transmittance of over 90%, has an elasticity of over 1700%, has an excellent dielectric constant, and has a high resistance of over 10 MΩ.

[0054]

[0055] A capacitive touch sensor according to an embodiment of the present invention comprises a capacitive touch sensor layer and an electrode disposed at the edge of the capacitive touch sensor layer. The capacitive touch sensor layer is manufactured by the method described above.

[0056]

[0057] Example: Manufacturing of a capacitive touch sensor layer

[0058] Example 1 (BB1): 2.00 g of PVC powder (Scientific Polymer Products, USA) was added to 75 ml of THF (DAEJUNG, Korea) and stirred to completely dissolve it. Then, 2.00 g of BB (Tokyo Chemical Industry, Japan) was added to this mixture, and the mixture was stirred at 600 rpm for 4 hours using a stirrer. After stirring, the mixture was poured into a Petri dish, and the solvent was removed by evaporating it at room temperature for 3 days. The thickness of the prepared capacitive touch sensor layer was 500 µm.

[0059]

[0060] Example 2 (BB2): Prepared in the same manner as Example 1, except that 1.26g of PVC and 2.53g of BB were added.

[0061]

[0062] Example 3 (BB3): Prepared in the same manner as Example 1, except that 0.92g of PVC and 2.77g of BB were added.

[0063]

[0064] Example 4 (BB5): Prepared in the same manner as Example 1, except that 0.60g of PVC and 3.01g of BB were added.

[0065]

[0066] Comparative Example 1 (DBP1): Prepared in the same manner as Example 1, except that 2.04g of PVC was added and 2.04g of Dibutyl phthalate (DBP) was added instead of BB.

[0067]

[0068] Comparative Example 2 (DBP2): Prepared in the same manner as Comparative Example 1, except that 1.30g of PVC and 2.60g of DBP were added.

[0069]

[0070] Comparative Example 3 (DBP3): Prepared in the same manner as Comparative Example 1, except that 0.95g of PVC and 2.86g of DBP were added.

[0071]

[0072] Comparative Example 4 (DBP5): Prepared in the same manner as Comparative Example 1, except that 0.62g of PVC and 3.11g of DBP were added.

[0073]

[0074] Comparative Example 5 (TBT1): Prepared in the same manner as Example 1, except that 2.05g of PVC was added and 2.05g of Tributyl Trimellitate (TBT) was added instead of BB.

[0075]

[0076] Comparative Example 6 (TBT2): Prepared in the same manner as Comparative Example 5, except that 1.31g of PVC and 2.60g of TBT were added.

[0077]

[0078] Comparative Example 7 (TBT3): Prepared in the same manner as Comparative Example 5, except that 0.96g of PVC and 2.88g of TBT were added.

[0079]

[0080] Comparative Example 8 (TBT5): Prepared in the same manner as Comparative Example 5, except that 0.63g of PVC and 3.14g of TBT were added.

[0081]

[0082] Preparation Example: Preparation of triboelectric nanogenerators

[0083] To analyze electrical characteristics, triboelectric nanogenerators were fabricated using the capacitive touch sensor layers of the examples and comparative examples and a PVC film. The capacitive touch sensor layers of the examples and comparative examples were each cut to a size of 2 cm x 2 cm, an ITO-PET electrode was placed on the bottom, and an acrylic substrate was placed below the ITO-PET electrode. Additionally, an Al electrode was placed on top of a 2 cm x 2 cm nylon sheet, and another acrylic substrate was placed on top of the Al electrode. These were arranged so that the capacitive touch sensor layers and the nylon sheet faced each other, maintaining a gap of 8 mm between them (see Fig. 2).

[0084] The following experiments were performed using an oscilloscope (TBS2204B, Tektronix, USA), an electric meter (6514, Keithley, USA), a low-noise current amplifier (DLPCA-200, Femto, Germany), and a high-voltage probe (P5100A, Tektronix, USA).

[0085]

[0086] Experimental Example: Analysis of Output Voltage Characteristics

[0087] The output voltage of the triboelectric nanogenerator including the electrostatic touch sensor layer of the example and comparative example was measured, and the results are shown in Fig. 3.

[0088] Referring to Fig. 3, the output voltage increased and then decreased in all types of plasticizers until the weight ratio of PVC to plasticizer reached 1:2, and the example using BB showed a superior output voltage compared to the comparative example using other plasticizers.

[0089]

[0090] Experimental Example: Power Density Characteristics Analysis

[0091] The power density of triboelectric nanogenerators including the capacitive touch sensor layers of Example 2, Comparative Example 2 and 6 was measured by connecting an external resistance from 10 kΩ to 10 GΩ, and the results are shown in Fig. 4.

[0092] Referring to Fig. 4, the example using BB showed superior power density compared to the comparative example using other plasticizers.

[0093]

[0094] Experimental Example: Measurement of Dielectric Constant

[0095] The dielectric constants of the capacitive touch sensor layers of the PVC film, Example 2, Comparative Example 2 and 6 were measured, and the results are shown in Fig. 5.

[0096] Referring to Figure 5, when BB was used under 5 Hz conditions, the dielectric constant increased 46 times compared to when PVC film was used, and showed a very high value compared to when other plasticizers were used.

[0097]

[0098] Experimental Example: Measurement of Surface Potential

[0099] The surface potential of the PVC film, Example 2, Comparative Example 2 and 6 capacitive touch sensor layers was measured. The surface potential was measured for 3 hours after 100 contact-separation cycles using nylon as the triboelectric positive charge material, and the results are shown in Fig. 6.

[0100] Referring to Fig. 6, it can be seen that Example 2, which uses BB as a plasticizer, exhibits the highest negative surface potential.

[0101]

[0102] Manufacturing Example: Manufacturing of a capacitive touch sensor

[0103] To analyze the performance as a capacitive touch sensor, a capacitive touch sensor was manufactured using the capacitive touch sensor layer of Example 2. A one-dimensional capacitive touch sensor (1D-TPS) was manufactured by cutting the capacitive touch sensor layer of Example 2 into 2 cm x 9 cm and attaching carbon tape to the opposite side in the far direction, and a two-dimensional capacitive touch sensor (2D-TPS) was manufactured by cutting the capacitive touch sensor layer of Example 2 into 7 cm x 7 cm and attaching carbon tape to all four sides (see FIGS. 7 and 8).

[0104]

[0105] Experimental Example: Current measurement according to contact position (1D-TPS)

[0106] Using the previously manufactured one-dimensional capacitive touch sensor (1D-TPS), the output current was measured by pressing sequentially from position 1 to position 7 in FIG. 7, and the results are shown in FIG. 9. E1 is the left edge in FIG. 7, and E2 is the right edge.

[0107] Referring to FIG. 9, the contact position and output current showed an inverse relationship in both the case of no extension (Fig. 7(a)) and the case of 50% extension (Fig. 7(b)), so it can be seen that the capacitive touch sensor of the present invention has excellent elasticity, stability, and sensitivity.

[0108] Figure 10 is the result of calculating the output current measured in Figure 9 using the following mathematical formula 1.

[0109] [Mathematical Formula 1]

[0110]

[0111] (I1 and I2 are measured current values, L1 and L2 are the lengths from the contact point to both electrodes, respectively, and R1 and R2 are resistances.)

[0112] Referring to Figure 10, it can be seen that the slope of the actual contact position relative to the calculated position before and after elongation is greater than 0.95, showing a very low error compared to the ideal slope of 1.

[0113]

[0114] Experimental Example: Current Measurement According to Contact Position (2D-TPS)

[0115] Using the previously manufactured 2D capacitive touch sensor (2D-TPS), the output current was measured after contacting the intersection points 9, 10, 14, and 15 of FIG. 8(b), and the results are shown in FIG. 11.

[0116] In addition, the output current measured in Fig. 11 was calculated using the following Equation 2 and the result is shown in Fig. 12, and the actual contact position and the result calculated using Equation 2 are compared and shown in Fig. 13.

[0117] [Mathematical Formula 2]

[0118]

[0119] (I1 to I4 are measured current values, L1 to L4 are the lengths from the contact position to both electrodes, respectively, and R1 to R4 are resistances.)

[0120] Referring to Fig. 13, the actual contact position is very close to the calculated position, so it can be seen that the measurement accuracy is excellent even in two dimensions.

[0121]

[0122] The present invention is not limited by the embodiments described above and the attached drawings, but is intended to be limited by the appended claims. Accordingly, various substitutions, modifications, and changes may be made by those skilled in the art within the scope of the technical concept of the present invention as described in the claims, without departing from the technical spirit of the invention, and such are also to be considered to fall within the scope of the present invention.

Claims

1. Poly vinyl chloride(PVC) and Containing butyl benzoate (BB), Capacitive touch sensor composition.

2. In Paragraph 1, The weight ratio of the above PVC and BB is 1:1.5 to 1:2.5, Capacitive touch sensor composition.

3. A step of preparing a PVC solution by dissolving poly vinyl chloride (PVC) in a solvent; A step of preparing a mixture by adding butyl benzoate (BB) to the above PVC solution and A step comprising removing the solvent of the above mixture, Method for manufacturing a capacitive touch sensor layer.

4. In Paragraph 3, In the step of preparing the above mixture, the weight ratio of PVC to BB is 1:1.5 to 1:2.5, Method for manufacturing a capacitive touch sensor layer.

5. In Paragraph 3, The above solvent is Tetrahydrofuran (THF), Method for manufacturing a capacitive touch sensor layer.

6. Includes a capacitive touch sensor layer and an electrode disposed at the edge of the capacitive touch sensor layer, and The above-mentioned capacitive touch sensor layer comprises Poly vinyl chloride (PVC) and Butyl benzoate (BB), Capacitive touch sensor.

7. In Paragraph 6, The weight ratio of the above PVC and BB is 1:1.5 to 1:2.5, Capacitive touch sensor.

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