Flexible electroluminescent device, multi-mode sensing device, application of flexible electroluminescent device and multi-mode sensing device, and health monitoring system

Abstract

The invention belongs to the technical field of sensors, and particularly relates to a flexible electroluminescent device, a multi-mode sensing device, application of the multi-mode sensing device and a health monitoring system. According to the invention, the high-molecular polymer is used as a flexible substrate to endow the electroluminescent layer with good mechanical flexibility, and the dielectric compound enhances the luminous intensity by improving the dielectricity of the luminescent layer; by introducing the conductive agent, the light-emitting voltage can be reduced, charges are effectively enhanced, and particularly, the current density is improved through electron injection. Meanwhile, the conductive agent optimizes the interface between the luminescent layer and the electrode and improves the current transmission characteristic, so that the stability of the electroluminescent material is improved, and the service life of the electroluminescent material is prolonged. According to the invention, the transparent top electrode has excellent light transmission and can generate stronger light output; the light-emitting layer has relatively high light-emitting efficiency and current density; the flexible PCB ensures good flexibility of the device, and the silver-plated electrode enables stable and low contact resistance between the PCB electrode and the light-emitting layer.

Description

Technical Field

[0001] The present invention belongs to the field of sensor technology, and specifically relates to a flexible electroluminescent device, a multimodal sensing device and its application, and a health monitoring system. Background Art

[0002] Multimodal sensing devices are a technology that can obtain information from multiple sensing channels at the same time, usually combining different types of sensors to provide more comprehensive and accurate data analysis. With the continuous development of flexible electronics, artificial intelligence and smart hardware, multimodal sensing technology has been widely used in various smart devices and systems. Combining multimodal sensing technology with flexible electronics technology has shown great potential, especially in the field of health monitoring. Flexible electronics technology enables sensors to better fit and interact with the human body, such as wearable devices, flexible sensor patches, etc., which can monitor physiological parameters such as body temperature, heart rate, and blood oxygen in real time. The data collected by these sensors is analyzed through artificial intelligence algorithms, which can provide personalized health management solutions, timely warn of health risks, and help users maintain optimal health.

[0003] Although multimodal devices have made significant breakthroughs in perception capabilities, their display functions are still relatively limited, and they usually require the help of external display devices to present perception information, which increases the complexity of use. In order to solve this problem, one of the current research focuses is to integrate electroluminescent devices in multimodal devices to enable them to have in-situ information display capabilities, thereby achieving smarter interactive functions. At present, common display technologies include light-emitting diodes. Although light-emitting diodes have high brightness, they are relatively hard and are not suitable for wearable devices. Therefore, a flexible light-emitting device is needed to be suitable for wearable devices. Summary of the invention

[0004] The purpose of the present invention is to provide a flexible electroluminescent device, a multimodal sensing device and its application, and a health monitoring system.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides a flexible electroluminescent device, comprising a transparent top electrode, an electroluminescent layer and a bottom electrode which are stacked in sequence; The raw materials for preparing the electroluminescent layer include luminescent materials, dielectric compounds, high molecular polymers and conductive agents; The bottom electrode is a flexible PCB with a silver-plated surface.

[0006] Preferably, the material of the transparent top electrode comprises hydrogel or indium tin oxide; The thickness of the bottom electrode is 120-150 μm; the thickness of the electroluminescent layer is 90-110 μm; and the thickness of the transparent top electrode is 0.8-1.2 mm.

[0007] Preferably, the dielectric compound includes at least one of BaTiO3, SrTiO3 and PbTiO3; The high molecular polymer includes at least one of polyvinylidene fluoride-hexafluoropropylene copolymer, thermoplastic polyurethane elastomer rubber, polydimethylsiloxane, polyvinylidene fluoride and polyurethane; The conductive agent includes at least one of PEDOT:PSS and silver nanowires; The luminescent material comprises at least one of ZnS:Cu, ZnS:Mn and ZnS:Al; The mass ratio of the luminescent material, the dielectric compound and the high molecular polymer is 9-11:4-6:4-6; The mass ratio of the luminescent material to the conductive agent is 9-11:0.9-1.1.

[0008] The present invention also provides a multimodal sensing device, which comprises an electroluminescent unit, an insulating layer and a sensor unit stacked in sequence from top to bottom; The electroluminescent unit is the flexible electroluminescent device described in the above technical solution; The sensor unit includes a sensor top electrode and a temperature sensor and a pressure sensor which are arranged in parallel at the bottom of the sensor top electrode and do not contact each other; The temperature sensor comprises a temperature sensing layer and a temperature sensing bottom electrode which are stacked in sequence; The pressure sensor comprises a pressure sensing layer and a pressure sensing bottom electrode which are stacked in sequence; The temperature sensing layer and the pressure sensing layer are in contact with the top electrode of the sensor; The surface of the pressure sensing layer has a protrusion, and the side having the protrusion is in contact with the pressure sensing bottom electrode.

[0009] Preferably, the material of the insulating layer includes polyimide, polyethylene terephthalate, polytetrafluoroethylene, polyvinyl chloride, polyvinyl pyrrolidone or polyethylene naphthalate; and the thickness of the insulating layer is 40-60 μm.

[0010] Preferably, the top electrode of the sensor is a Cu conductive tape; the thickness of the top electrode of the sensor is 90-110 μm.

[0011] Preferably, the material of the pressure sensing layer includes PVA, H3PO4 and MWCNTs; the mass ratio of PVA, H3PO4 and MWCNTs is 2-4: 0.2-0.4: 0.009-0.011; The thickness of the pressure sensing layer is 220-260 μm; The pressure sensing bottom electrode is a Cu conductive tape, and the thickness of the pressure sensing bottom electrode is 90-110 μm.

[0012] Preferably, the material of the temperature sensing layer includes PEDOT:SS, AgNO3 and PVA; the mass ratio of PEDOT:SS, AgNO3 and PVA is 0.3-0.5:0.02-0.04:2-4; The thickness of the temperature sensing layer is 95-105 μm; The temperature sensing bottom electrode is a Cu conductive tape, and the thickness of the temperature sensing bottom electrode is 90-110 μm.

[0013] The present invention also provides the application of the multimodal sensing device described in the above technical solution in health monitoring.

[0014] The present invention also provides a health monitoring system, comprising: A sensor, wherein the sensor is the multimodal sensing device described in the above technical solution; an analog-to-digital converter connected to a temperature sensor in the sensor; A capacitance-to-digital converter connected to a pressure sensor in the sensor; A single chip microcomputer is connected to the analog-to-digital converter and the capacitance-to-digital converter respectively; A relay, used for connecting the sensor to the single chip microcomputer; AC driver, and the relay is connected.

[0015] The present invention provides a flexible electroluminescent device, comprising a transparent top electrode, an electroluminescent layer and a bottom electrode which are stacked in sequence; the raw materials for preparing the electroluminescent layer include a luminescent material, a dielectric compound, a high molecular polymer and a conductive agent; the bottom electrode is a flexible PCB with a silver-plated surface.

[0016] In the present invention, the high molecular polymer as a flexible matrix gives the electroluminescent layer good mechanical flexibility, and the dielectric compound enhances the luminous intensity by improving the dielectric property of the luminescent layer. Although the luminescent layer composed of the luminescent material, the dielectric compound, and the high molecular polymer has a high luminous efficiency, its driving voltage is high, so the conductive agent is introduced to reduce the luminous voltage. The conductive agent has excellent conductivity and can effectively enhance the injection of charges, especially electrons, and increase the current density. At the same time, it optimizes the interface between the luminescent layer and the electrode, improves the current transmission characteristics, and thus enhances the stability and service life of the electroluminescent material.

[0017] In the present invention, the transparent top electrode has excellent light transmittance and can produce stronger light output; the light-emitting layer has high luminous efficiency and current density; the flexible PCB ensures good flexibility of the device, and the silver-plated electrode enables a stable and low contact resistance between the PCB electrode and the light-emitting layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a multimodal sensing device provided by the present invention, wherein: 1-transparent top electrode, 2-electroluminescent layer, 3-bottom electrode, 4-insulating layer, 5-sensor top electrode, 6-temperature sensing layer, 7-pressure sensing layer, 8-temperature sensing bottom electrode, 9-pressure sensing bottom electrode; Figure 2 This is a cross-sectional electron microscope image of the pressure sensing layer obtained in Example 1; Figure 3 is an electron microscope image of the ZnS:Cu powder used in Example 1; Figure 4 The sensitivity curve diagram of the pressure sensor in the sensing device obtained in Example 2; Figure 5 This is a durability test curve diagram of the pressure sensor in the sensing device obtained in Example 2; Figure 6 The sensitivity curve diagram of the temperature sensor in the sensing device obtained in Example 2; Figure 7 The cyclic response curve diagram of the temperature sensor in the sensing device obtained in Example 2; Figure 8 This is a graph of the luminous intensity of the electroluminescent unit in the sensing device obtained in Example 2 at different voltages; Fig. 9 This is a time durability diagram of the electroluminescent unit in the sensing device obtained in Example 2; Fig.10 This is a diagram of a human pulse signal detected by a sensing device obtained in Example 2; Fig.11 This is an enlarged picture of the human pulse signal; Fig.12 This is a curve diagram of human body temperature detected by the sensing device obtained in Example 2; Fig.13 The curve diagram of the human wrist bending detected by the sensing device obtained in Example 2; Fig.14 A schematic diagram of the structure of the health monitoring system provided by the present invention; Fig.15 Physical picture of the interface between the health monitoring system, body temperature and pulse, and the host computer; Fig.16 Physical picture of different joint activities monitored by the health monitoring system. DETAILED DESCRIPTION

[0019] The present invention provides a flexible electroluminescent device, comprising a transparent top electrode, an electroluminescent layer and a bottom electrode which are stacked in sequence; The raw materials for preparing the electroluminescent layer include luminescent materials, dielectric compounds, high molecular polymers and conductive agents; The bottom electrode is a flexible PCB with a silver-plated surface.

[0020] In the present invention, the material of the transparent top electrode preferably includes hydrogel or indium tin oxide; the thickness of the transparent top electrode is preferably 0.8-1.2 mm, specifically 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm.

[0021] In the present invention, when the material of the transparent top electrode is hydrogel, the raw materials for preparing the transparent top electrode include acrylamide, N,N-methylenebisacrylamide and N,N,N',N'-tetramethylethylenediamine.

[0022] In the present invention, the preparation method of the transparent top electrode preferably includes the following steps: dissolving 3.5g acrylamide, 0.6g lithium chloride and 7mg N,N-methylenebisacrylamide in 15mL deionized water, and magnetically stirring at 500rpm for 15min at room temperature. Afterwards, 1.5g glycerol is added, and the mixed solution is magnetically stirred at 500rpm for 10min at room temperature. Then, 10μL of N,N,N',N'-tetramethylethylenediamine solution is added, and the mixed solution is magnetically stirred at 500rpm for 5min at room temperature. Finally, 7mg sodium persulfate is added to the mixed solution, and after sufficient stirring, the solution is poured into a glass culture dish and dried in an oven at 65°C for 15min.

[0023] In the present invention, the bottom electrode is a flexible PCB with a silver-plated surface; the thickness of the bottom electrode is preferably 120~150μm, specifically 120μm, 130μm, 140μm, 150μm. In the present invention, a silver-plated flexible PCB circuit board is used as the bottom electrode of the electroluminescent unit, and has a stable and low contact resistance with the light-emitting layer, which is the key reason for controlling the light-emitting device to display specific information. In the present invention, a transparent top electrode is used to achieve high light transmittance; the bottom electrode is formed by combining a silver-plated electrode with a flexible PCB to ensure good conductivity and mechanical flexibility. Overall, the electroluminescent device has high brightness, excellent bending performance and excellent long-term stability, and is suitable for flexible electronics and wearable display applications.

[0024] In the present invention, the dielectric compound preferably includes at least one of BaTiO3, SrTiO3 and PbTiO3; the high molecular polymer preferably includes at least one of polyvinylidene fluoride-hexafluoropropylene copolymer, thermoplastic polyurethane elastomer rubber, polydimethylsiloxane, polyvinylidene fluoride and polyurethane; the conductive agent preferably includes at least one of PEDOT:PSS and silver nanowires (AgNWs); the luminescent material preferably includes at least one of ZnS:Cu, ZnS:Mn and ZnS:Al. In the present invention, the mass ratio of the luminescent material, the dielectric compound and the high molecular polymer is preferably 9~11:4~6:4~6; more preferably 10:5:5; the mass ratio of the luminescent material and the conductive agent is preferably 9~11:0.9~1.1, more preferably 10:1. In the present invention, the thickness of the electroluminescent layer is preferably 90~110μm, specifically 90μm, 100μm, 110μm.

[0025] In the present invention, the method for preparing the electroluminescent layer preferably comprises the following steps: The luminescent material, dielectric compound, high molecular polymer and conductive agent are dispersed in an organic solvent and stirred to obtain a mixed solution; the mixed solution is poured into a culture dish and dried to obtain the electroluminescent device.

[0026] In the present invention, the organic solvent preferably includes N,N'-dimethylformamide. The present invention has no particular limitation on the amount of the organic solvent, as long as the raw materials can be evenly dispersed. In the present invention, the stirring speed is preferably 800 rpm, and the time is preferably 5 hours. In the present invention, the drying temperature is preferably 60°C, and the time is preferably 2 hours.

[0027] The present invention also provides a multimodal sensing device, which comprises an electroluminescent unit, an insulating layer and a sensor unit stacked in sequence from top to bottom; The electroluminescent unit is the flexible electroluminescent device described in the above technical solution; The sensor unit includes a sensor top electrode and a temperature sensor unit and a pressure sensor unit which are arranged in parallel at the bottom of the sensor top electrode and do not contact each other; The temperature sensor unit comprises a temperature sensing layer and a temperature sensing bottom electrode which are stacked in sequence; The pressure sensor unit comprises a pressure sensing layer and a pressure sensing bottom electrode which are stacked in sequence; The temperature sensing layer and the pressure sensing layer are in contact with the top electrode of the sensor; The surface of the pressure sensing layer has a protrusion, and the side having the protrusion is in contact with the pressure sensing bottom electrode.

[0028] In the present invention, the sensor top electrode is preferably a Cu conductive tape; the thickness of the sensor top electrode is preferably 90-110 μm, specifically 90 μm, 100 μm, or 110 μm.

[0029] In the present invention, the material of the insulating layer is preferably polyimide (PI), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinyl pyrrolidone (PVP) or polyethylene naphthalate (PEN); the thickness of the insulating layer is preferably 40~60μm, specifically 40μm, 50μm, 60μm.

[0030] In the present invention, the material of the pressure sensing layer preferably includes PVA, H3PO4 and MWCNTs; the mass ratio of the PVA, H3PO4 and MWCNTs is preferably 2~4:0.2~0.4:0.009~0.011, and more preferably 3:0.3:0.01; the thickness of the pressure sensing layer is preferably 220~260μm, and specifically can be 220μm, 230μm, 240μm, 250μm, 260μm. In the present invention, the surface of the pressure sensing layer has protrusions, and the height of the protrusions is preferably 140~160μm, and more preferably 150μm; the protrusions are preferably distributed in an array.

[0031] In the present invention, the method for preparing the pressure sensing layer preferably comprises the following steps: first mixing PVA and deionized water to obtain a PVA solution; The PVA solution, H3PO4 and MWCNTs are mixed for a second time to obtain a mixed solution; The mixed liquid is poured into a 3D printed mask and dried to obtain the pressure sensing layer.

[0032] In the present invention, the mass concentration of the PVA solution is preferably 10%. In the present invention, the temperature of the first mixing is preferably 95°C, the first mixing is preferably performed under stirring, the stirring speed is preferably 1500 rpm, and the time is preferably 5 hours.

[0033] In the present invention, the second mixing is preferably carried out under stirring conditions, the stirring speed is preferably 1000 rpm, and the time is preferably 5 hours. In the present invention, the drying temperature is preferably 60° C., and the time is preferably 3 hours.

[0034] In the present invention, a template method is used to prepare a pressure sensing layer with a pyramid microstructure, thereby improving the sensitivity of the pressure sensor. The present invention uses phosphoric acid and multi-walled carbon nanotubes (MWCNTs) to dope polyvinyl alcohol (PVA), which greatly improves the sensitivity compared to pure phosphoric acid.

[0035] In the present invention, the pressure sensor adopts an upper and lower parallel plate electrode structure, with a pressure sensing layer (dielectric layer) with a microstructure in the middle. The dielectric layer is composed of PVA, H3PO4 and MWCNTs. Among them, the addition of H3PO4 causes mobile ions to be generated inside the PVA, and under the action of an external electric field, an electric double-layer structure is formed between the upper and lower electrodes and the dielectric layer. Compared with traditional non-ionic capacitors, this ion effect significantly improves the sensitivity of the sensor. In addition, MWCNTs have excellent charge storage and transmission capabilities, which further enhances the sensing performance. The microstructure of the dielectric layer is prepared by 3D printing a pyramid mask. The microstructure can effectively improve the pressure response characteristics. As the pressure increases, the contact area between the microstructure on the surface of the dielectric layer and the electrode increases, which in turn leads to an increase in the capacitance value. The pressure sensor exhibits high sensitivity and excellent stability. The performance has not been significantly attenuated in more than 2,000 pressure cycle tests, showing excellent performance advantages.

[0036] In the present invention, the pressure sensing bottom electrode is preferably a Cu conductive tape, and the thickness of the pressure sensing bottom electrode is preferably 90-110 μm, specifically 90 μm, 100 μm, or 110 μm.

[0037] In the present invention, the material of the temperature sensing layer preferably includes PEDOT:SS, AgNO3 and PVA; the mass ratio of PEDOT:SS, AgNO3 and PVA is preferably 0.3~0.5:0.02~0.04:2~4, and further preferably 0.4:0.03:3; the thickness of the temperature sensing layer is preferably 95~105μm, specifically 95μm, 100μm, 105μm.

[0038] In the present invention, the method for preparing the temperature sensing layer preferably comprises the following steps: Dissolving PVA in deionized water to obtain a PVA solution; Adding the AgNO3 aqueous solution into the PVA solution, and stirring to obtain a mixed solution; Adding PEDOT:SS to the mixed solution and continuing stirring to obtain a slurry; The slurry is dried to obtain the temperature sensing layer.

[0039] In the present invention, the mass concentration of the PVA solution is preferably 10%. In the present invention, the dissolution temperature is preferably 95°C, the dissolution is preferably carried out under stirring, the stirring speed is preferably 1500 rpm, and the time is preferably 5 hours.

[0040] In the present invention, the concentration of the AgNO3 aqueous solution is preferably 0.2 mol / L; the stirring temperature is room temperature, the stirring speed is preferably 1000 rpm, and the time is preferably 1 hour.

[0041] In the present invention, the rotation speed of the continuous stirring is preferably 1000 rpm, and the time is preferably 3 hours. In the present invention, the drying temperature is preferably 60° C., and the time is preferably 3 hours.

[0042] In the present invention, the temperature sensing layer utilizes poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:SS) and AgNO3 doped PVA, and the temperature response sensitivity is greatly improved compared with the simple doping of PEDOT:PSS.

[0043] In the present invention, the temperature sensing layer is composed of PEDOT:PSS, AgNO3 and PVA, wherein PEDOT:PSS is the main temperature-sensitive material, showing good temperature response performance. As the temperature rises, the water molecules inside PEDOT:PSS are gradually released to the external environment, causing the shell to shrink and the distance between adjacent core-shells to decrease, thereby enhancing the ability of electrons to transition between core-shell structures and reducing their resistance. This mechanism constitutes the core response principle of the temperature sensor. In addition, the introduction of ions significantly improves the sensitivity of the temperature response, giving the sensor higher detection accuracy and stability. In addition, the preparation process of the temperature sensing layer is simple, no toxic solvents are required, the film-making speed is fast and the effect is excellent.

[0044] In the present invention, the temperature sensing bottom electrode is preferably a Cu conductive tape, and the thickness of the temperature sensing bottom electrode is preferably 90-110 μm, specifically 90 μm, 100 μm, or 110 μm.

[0045] The present invention has no special limitation on the method for preparing the multimodal sensing device, and the various parts can be assembled and packaged according to the structure of the device.

[0046] Figure 1 This is a schematic diagram of the structure of the multimodal sensing device provided by the present invention, wherein 1 is a transparent top electrode, 2 is an electroluminescent layer, 3 is a bottom electrode, 4 is an insulating layer, 5 is a sensor top electrode, 6 is a temperature sensing layer, 7 is a pressure sensing layer, 8 is a temperature sensing bottom electrode, and 9 is a pressure sensing bottom electrode.

[0047] The present invention also provides the application of the multimodal sensing device described in the above technical solution in health monitoring.

[0048] The present invention also provides a health monitoring system, comprising: A sensor, wherein the sensor is the multimodal sensing device described in the above technical solution; an analog-to-digital converter (ADC), connected to a temperature sensor unit in the sensor; A capacitance digital converter (FDC2214), connected to the pressure sensor unit in the sensor; A single chip microcomputer is connected to the analog-to-digital converter and the capacitance-to-digital converter respectively; A relay, used for connecting the sensor to the single chip microcomputer; AC driver, and the relay is connected.

[0049] In the present invention, the single chip microcomputer is preferably an STM32 single chip microcomputer, a 51 single chip microcomputer, an FPGA or an arduion. In the present invention, the relay is preferably a 22-way relay.

[0050] In the present invention, the single chip microcomputer is preferably connected to a host computer for displaying the test data for comparison with the display data of the electroluminescent unit in the sensor.

[0051] In the present invention, the structural diagram of the health monitoring system is as follows Fig.14 As shown below, combined Fig.14 The health monitoring system is described as follows: The sensor can detect external stimuli, the temperature sensor unit detects body temperature, the pressure sensor unit detects pulse and joint movement, and converts different physiological signals into electrical signals, body temperature changes into current changes, pulse beats and joint movements into capacitance changes. ADC can collect resistance information, FDC2214 can collect capacitance information, and transmit the data to the single-chip microcomputer. After the single-chip microcomputer processes the collected data, it controls the relay through electrical signals to realize the intelligent information display of the electroluminescent device. The system effectively solves the problem of insufficient display function in health monitoring, and provides an innovative solution for health monitoring with real-time visualization, low-power interaction and intelligent feedback.

[0052] The present invention provides a multimodal device with pressure and temperature sensing and electroluminescent display functions, and designs a health monitoring system with sensing and display interaction based on the device characteristics. The health monitoring system provided by the present invention consists of three parts. The sensing part consists of pressure and temperature sensors, and the two sensors are located in the same plane. The display part consists of an electroluminescent device, which is located above the sensing layer to form an efficient and harmonious three-dimensional structure. The external integrated circuit is used for data acquisition, transmission and analysis, and drives the light-emitting device to display information to realize human health information monitoring. The external integrated circuit realizes the collection, data processing and analysis of pressure and temperature information, and controls the light-emitting display through a relay module, and finally constructs a health monitoring system with sensing and display interaction.

[0053] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0054] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Example 1 3.5 g acrylamide, 0.6 g lithium chloride and 7 mg N,N-methylenebisacrylamide were dissolved in 15 mL deionized water, and magnetically stirred at 500 rpm for 15 min at room temperature; then, 1.5 g glycerol was added, and magnetically stirred at 500 rpm for 10 min at room temperature; then, 10 μL of N,N,N',N'-tetramethylethylenediamine solution was added, and magnetically stirred at 500 rpm for 5 min at room temperature; finally, 7 mg sodium persulfate was added to the mixed solution, and after sufficient stirring, the solution was poured into a glass culture dish and dried in an oven at 65°C for 15 min to obtain a hydrogel electrode with a thickness of 1 mm as a transparent top electrode; 0.8 g ZnS:Cu, 0.4 g PVDF-HFP and 0.4 g BaTiO3 were dissolved in 3 mL N,N'-dimethylformamide, and then magnetically stirred at 800 rpm for 1 h at room temperature. Then, 0.08 g PEDOT:PSS was added, and magnetically stirred at 800 rpm for 5 h. The mixed solution was poured into a glass petri dish and dried in an oven at 60 °C for 2 h to obtain an electroluminescent layer with a thickness of 100 μm. A flexible PCB with a surface silver plating of 140 μm in thickness is used as the bottom electrode of the electroluminescent unit; The transparent top electrode, the electroluminescent layer and the bottom electrode are assembled in order to obtain the flexible electroluminescent device.

[0056] Example 2 3g of PVA was dissolved in 7g of deionized water, and magnetically stirred at 1500rpm for 5h at 95℃ to obtain a PVA aqueous solution with a mass fraction of 10%; then, 0.3g of H3PO4 solution and 10mg of MWCNTs powder were added to the PVA aqueous solution, and magnetically stirred at 1000rpm for 5h at room temperature; the mixed solution was poured into the 3D printed mask, and dried in an oven at 60℃ for 3h to obtain a pressure sensing layer with a thickness of 250μm, in which the height of the protrusions was 150μm; 3g PVA was dissolved in 7g deionized water, and magnetically stirred at 1500rpm for 5h at 95℃ to obtain a PVA aqueous solution with a mass fraction of 10%; then, 1mL of AgNO3 aqueous solution (0.2mol / L) was taken and added to the PVA aqueous solution, and magnetically stirred at 1000rpm for 1h at room temperature; then, 0.4g PEDOT:PSS was added, and magnetically stirred at 1000rpm for 3h, and finally, dried in an oven at 60℃ for 3h to obtain a temperature sensing layer with a thickness of 100μm; The electroluminescent device obtained in Example 1 is used as an electroluminescent unit; The PI layer with a thickness of 50 μm is used as the insulation layer; A Cu conductive tape with a thickness of 100 μm was used as the temperature sensing bottom electrode; A Cu conductive tape with a thickness of 100 μm was used as the pressure sensing bottom electrode; The multimodal sensing device is assembled according to its structure to obtain the multimodal sensing device.

[0057] Performance Testing Test Example 1 Characterization: Figure 2 This is a cross-sectional electron microscope image of the pressure sensing layer obtained in Example 1. Figure 2 It can be seen that the surface of the pressure sensing layer has a pyramid microstructure; Figure 3 is an electron microscope image of the ZnS:Cu powder used in Example 1. Figure 3 It can be seen that the ZnS:Cu particle size is 40 μm.

[0058] Test Example 2 Figure 4 is a sensitivity curve diagram of the pressure sensor in the sensing device obtained in Example 2, from Figure 4 It can be seen that by applying different pressures (0~60kPa) to the pressure sensor, a sensitivity curve is obtained, and the sensitivity is 500kPa -1 .

[0059] Figure 5 The durability test curve of the pressure sensor in the sensing device obtained in Example 2 is shown in FIG. Figure 5 It can be seen that the linear motor was used to impact the pressure sensor more than 2,000 times, and there was no obvious performance degradation.

[0060] Figure 6 is a sensitivity curve diagram of the temperature sensor in the sensing device obtained in Example 2, from Figure 6 It can be seen that when the temperature sensor is placed on the heating table and the set temperature is increased from 30℃ to 40℃, the current changes and the sensitivity is 3.5℃-1 .

[0061] Figure 7 The cyclic response curve of the temperature sensor in the sensing device obtained in Example 2 is shown in FIG. Figure 7 It can be seen that the temperature sensor is heated by using a UV heating lamp, from room temperature to 25°C and then to 45°C, and then the heating lamp is turned off and the temperature sensor temperature is waited to return to room temperature. Multiple cycles indicate that the temperature sensor has good cycling characteristics.

[0062] Figure 8 The luminous intensity diagram of the electroluminescent unit in the sensing device obtained in Example 2 under different voltages is shown in FIG. Figure 8 It can be seen that using an AC power box, at a frequency of 500Hz, AC power of different amplitudes (0~300V) is applied to both ends of the electroluminescent device. As the voltage increases, the luminous intensity continues to increase.

[0063] Fig. 9 The time durability diagram of the electroluminescent unit in the sensing device obtained in Example 2 is shown in FIG. Fig. 9 It can be seen that the AC driver is used to continuously power the electroluminescent device and the luminous intensity is tested for 2400 seconds without obvious attenuation.

[0064] Test Example 3 according to Fig.14 The structure shown assembles a health monitoring system and detects the body temperature, pulse and joint movement of the human body; Fig.10 This is a diagram of a human pulse signal detected by a sensing device obtained in Example 2. Fig.11 This is an enlarged picture of the human pulse signal; Fig.10 and 11 It can be seen that the health monitoring system integrating multimodal sensors can accurately collect human pulse signals and observe the three peaks of the pulse.

[0065] Fig.12 This is a curve diagram of human body temperature detected by the sensing device obtained in Example 2. Fig.12 It can be seen that the health monitoring system can detect that the current human body temperature is 36.7℃.

[0066] Fig.13 The curve diagram of the human wrist bending detected by the sensing device obtained in Example 2 is as follows: Fig.13 It can be seen that the health monitoring system can detect the change in sensor capacitance when the wrist is bent at different angles. As the bending angle increases, the capacitance change increases.

[0067] Fig.15 The physical picture of the health monitoring system monitoring body temperature and pulse and the host computer interface, from Fig.15It can be seen that the health monitoring system can detect the current human body temperature and pulse through multimodal sensors, and can display information through electroluminescent devices.

[0068] Fig.16 Physical diagram of different joint activities monitored by the health monitoring system, from Fig.16 It can be seen that the health monitoring system monitors different joint activities and can display the bending angle.

[0069] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A flexible electroluminescent device, characterized in that: It comprises a transparent top electrode, an electroluminescent layer and a bottom electrode which are stacked in sequence; The raw materials for preparing the electroluminescent layer include luminescent materials, dielectric compounds, high molecular polymers and conductive agents; The bottom electrode is a flexible PCB with a silver-plated surface.

2. The flexible electroluminescent device according to claim 1, characterized in that: The material of the transparent top electrode includes hydrogel or indium tin oxide; The thickness of the bottom electrode is 120-150 μm; the thickness of the electroluminescent layer is 90-110 μm; and the thickness of the transparent top electrode is 0.8-1.2 mm.

3. The flexible electroluminescent device according to claim 1, characterized in that: The dielectric compound includes at least one of BaTiO3, SrTiO3 and PbTiO3; The high molecular polymer includes at least one of polyvinylidene fluoride-hexafluoropropylene copolymer, thermoplastic polyurethane elastomer rubber, polydimethylsiloxane, polyvinylidene fluoride and polyurethane; The conductive agent includes at least one of PEDOT:PSS and silver nanowires; The luminescent material comprises at least one of ZnS:Cu, ZnS:Mn and ZnS:Al; The mass ratio of the luminescent material, the dielectric compound and the high molecular polymer is 9-11:4-6:4-6; The mass ratio of the luminescent material to the conductive agent is 9-11:0.9-1.

1.

4. A multimodal sensing device, characterized in that: It includes an electroluminescent unit, an insulating layer and a sensor unit stacked in sequence from top to bottom; The electroluminescent unit is the flexible electroluminescent device according to any one of claims 1 to 3; The sensor unit includes a sensor top electrode and a temperature sensor and a pressure sensor which are arranged in parallel at the bottom of the sensor top electrode and do not contact each other; The temperature sensor comprises a temperature sensing layer and a temperature sensing bottom electrode which are stacked in sequence; The pressure sensor comprises a pressure sensing layer and a pressure sensing bottom electrode which are stacked in sequence; The temperature sensing layer and the pressure sensing layer are in contact with the top electrode of the sensor; The surface of the pressure sensing layer has a protrusion, and the side having the protrusion is in contact with the pressure sensing bottom electrode.

5. The multimodal sensing device according to claim 4, characterized in that: The material of the insulating layer includes polyimide, polyethylene terephthalate, polytetrafluoroethylene, polyvinyl chloride, polyvinyl pyrrolidone or polyethylene naphthalate; the thickness of the insulating layer is 40-60 μm.

6. The multimodal sensing device according to claim 4, characterized in that: The top electrode of the sensor is a Cu conductive tape; the thickness of the top electrode of the sensor is 90-110 μm.

7. The multimodal sensing device according to claim 4, characterized in that: The material of the pressure sensing layer includes PVA, H3PO4 and MWCNTs; the mass ratio of PVA, H3PO4 and MWCNTs is 2-4: 0.2-0.4: 0.009-0.011; The thickness of the pressure sensing layer is 220-260 μm; The pressure sensing bottom electrode is a Cu conductive tape, and the thickness of the pressure sensing bottom electrode is 90-110 μm.

8. The multimodal sensing device according to claim 4, characterized in that: The material of the temperature sensing layer includes PEDOT:SS, AgNO3 and PVA; the mass ratio of PEDOT:SS, AgNO3 and PVA is 0.3-0.5:0.02-0.04:2-4; The thickness of the temperature sensing layer is 95-105 μm; The temperature sensing bottom electrode is a Cu conductive tape, and the thickness of the temperature sensing bottom electrode is 90-110 μm.

9. Application of the multimodal sensing device according to any one of claims 4 to 8 in health monitoring.

10. A health monitoring system, characterized in that: include: A sensor, wherein the sensor is a multimodal sensing device according to any one of claims 4 to 8; an analog-to-digital converter connected to a temperature sensor in the sensor; A capacitance-to-digital converter connected to a pressure sensor in the sensor; A single chip microcomputer is connected to the analog-to-digital converter and the capacitance-to-digital converter respectively; A relay, used for connecting the sensor to the single chip microcomputer; AC driver, and the relay is connected.

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