An oxide transistor with temperature-sensitive color-changing function and its application

Abstract

The disclosed oxide transistor with temperature-sensitive color change functionality comprises a substrate, an oxide conductive layer, an insulating layer, and an electrode assembly, constructed sequentially from bottom to top. The insulating layer comprises a solid electrolyte membrane, and the electrode assembly comprises a source electrode, a drain electrode, and a conductive interface connecting the source and drain electrodes. The conductive interface is an n-type semiconductor channel. The source, drain, and conductive interface are all made of metal oxides. The solid electrolyte membrane is composed of a mixture of thermochromic powder and a bioelectrolyte in a mass ratio of 1:20-100. This transistor can regulate the protons in the electrolyte according to temperature changes, exhibiting distinct color changes at different temperatures. It demonstrates significant advantages in neuromorphic computing and can be applied to neuromorphic devices to achieve functions such as temperature sensing, neuromorphic computing, and biomimetic color-changing electronic skin. It has potential applications in the construction of environmentally friendly, biocompatible, flexible, wearable neuromorphic platforms and human-computer interaction platforms.

Description

Technical Field

[0001] The present invention belongs to the technical field of information devices, and in particular relates to an oxide transistor with a temperature-sensitive color-changing function and applications thereof. Background Art

[0002] With the continuous advancement of big data analysis, artificial intelligence, machine learning, and natural language processing, there is a growing demand for computer storage capacity and processing speed. However, modern computer systems still rely on the von Neumann architecture to process massive amounts of data and information. In the von Neumann architecture, the storage and computing modules are physically separated, resulting in low information processing efficiency and high energy consumption. The brain, on the other hand, operates in a low-power, multi-path parallel, and efficient information processing mode. This operating mode has inspired the proposal of neuromorphic computing to overcome the von Neumann bottleneck. At the hardware level, the development of neuromorphic devices that can mimic the behavior of biological synapses is crucial for the realization of neuromorphic computing. Among them, neuromorphic transistors, which can simultaneously perform information transmission and learning operations, are a very promising type of neuromorphic device. These devices can be used to mimic the impulse response behavior between synapses and neurons, thereby emulating neuronal function.

[0003] At the same time, the human nervous system is a multimodal information processing system that can collaboratively process and respond to touch, vision, hearing, taste, and smell, enabling individuals to rapidly respond to the external environment. Based on this mechanism, biomimetic perceptual neuromorphic systems have been proposed, which can achieve dynamic and intelligent processing of the five senses. It is worth noting that temperature is also a significant factor influencing biological neural responses, and temperature perception is an important manifestation of the human body's response to the external environment. Human skin contains temperature-sensitive receptors, including cold receptors and thermoreceptors. When skin temperature rises, thermoreceptors activate, while when skin temperature drops, cold receptors activate. Furthermore, the body's temperature perception behavior is related to the intensity of the thermal stimulus and the duration of exposure. Furthermore, organisms can display a rich variety of colors, even dynamically changing skin color and pattern in response to changes in the external environment, thereby blending in with the surrounding color and achieving camouflage for individual protection. Inspired by the color changes on the surface of living organisms, biomimetic technologies are being used to create color-changing materials, such as electrochromics and photochromics. Therefore, integrating thermochromic materials with neuromorphic devices will broaden the research and application of neuromorphic electronics and has great practical significance. In view of this, we combine thermochromic and transistor technologies to propose an oxide transistor with thermochromic function and its application. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an oxide transistor with temperature-sensitive color-changing function and its application. The oxide transistor can realize proton regulation in the electrolyte according to temperature changes and has obvious color changes at different temperatures. The oxide transistor shows great advantages in neuromorphic computing and can be applied to neuromorphic devices to realize functions such as temperature perception, neuromorphic computing and bionic color-changing electronic skin. It has potential application prospects in the construction of green, environmentally friendly, biocompatible and flexible wearable neuromorphic platforms and human-computer interaction platforms.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: an oxide transistor with a temperature-sensitive color-changing function, including a substrate, an oxide conductive layer, an insulating layer and an electrode assembly built in sequence from bottom to top, the insulating layer is a solid electrolyte membrane, the electrode assembly includes a source electrode, a drain electrode and a conductive interface connecting the source electrode and the drain electrode, the conductive interface is an n-type semiconductor channel, the materials of the source electrode, the drain electrode and the conductive interface are all metal oxides, and the solid electrolyte membrane is formed by mixing thermochromic powder and bioelectrolyte in a mass ratio of 1:(20-100).

[0006] The present invention uses a solid electrolyte membrane mixed with thermochromic powder and bioelectrolyte as the insulating layer of the transistor. This hybrid membrane structure has multiple advantages: first, it inherits the non-toxic, biodegradable and low-cost characteristics of bioelectrolyte materials; second, the bioelectrolyte material is easily protonated under the action of acetic acid and has good proton conductivity; in addition, the membrane can also significantly change color with changes in temperature, which can fully utilize the characteristics of the thermochromic powder.

[0007] When an external electric field is applied to the oxide conductive layer of the oxide transistor with a temperature-sensitive color-changing function of the present invention, a unique ion / electron coupling phenomenon will be formed at the solid electrolyte membrane and the conductive interface under the stimulation of the electric field, and the ion / electron coupling phenomenon will change in an environment where the external temperature changes, and the solid electrolyte membrane will also have a color change behavior at different temperatures. The above-mentioned oxide transistor with a temperature-sensitive color-changing function has brain-like synaptic response behavior and learning behavior, and can be used for temperature perception. Moreover, due to the effective synaptic weight update between the source and the drain, the above-mentioned oxide transistor with a temperature-sensitive color-changing function can be used as a neuromorphic device in neuromorphic computing. At the same time, temperature changes will also cause the temperature-sensitive color-changing powder contained in the solid electrolyte membrane to produce obvious color changes, providing a novel implementation technology solution for bionic color-changing electronic skin.

[0008] Preferably, the bioelectrolyte is chitosan, which is readily available, low-cost, non-toxic, degradable, and has good proton conductivity, making it the preferred bioelectrolyte.

[0009] Preferably, the thickness of the insulating layer is 2-100 μm, the thickness of the source electrode and the drain electrode are 100-300 nm respectively, and the thickness of the conductive interface is 10-50 nm.

[0010] Preferably, the material of the oxide conductive layer is indium zinc oxide (IZO) or indium tin oxide (ITO), and the metal oxide is indium tin oxide (ITO), indium tungsten oxide (IWO), indium zinc oxide (IZO) or indium gallium zinc oxide (IGZO).

[0011] The method for preparing the above-mentioned oxide transistor with temperature-sensitive color change function comprises the following steps:

[0012] (1) A chitosan solution was obtained by a solution method: chitosan powder was dissolved in acetic acid solvent and deionized water at a mass ratio of 1:1:48 to obtain a 2 wt% chitosan solution at room temperature, and the solution was allowed to stand for 18 to 24 h to allow the chitosan powder to fully dissolve and form a uniform chitosan solution;

[0013] (2) mixing a thermochromic powder of a desired color with a chitosan solution in a certain mass ratio, wherein the mass ratio of the thermochromic powder to the chitosan is 1:(20-100), stirring the mixture with a magnetic stirrer at room temperature, and after the mixture is fully mixed, using a vacuum pump to remove air bubbles to obtain a mixed solution of the mixture;

[0014] (3) The substrate with the oxide conductive layer was ultrasonically cleaned with alcohol for multiple times, each time for 10 minutes, and then ultrasonically cleaned with deionized water for multiple times, each time for 10 minutes, and then the substrate with the oxide conductive layer was blown dry with nitrogen;

[0015] (4) adding the mixed solution obtained in step (2) dropwise onto the oxide conductive layer of the substrate, and uniformly coating the oxide conductive layer by drop coating;

[0016] (5) placing the substrate coated with the mixed solution on the oxide conductive layer into a drying oven and drying it at 40 to 50° C. for 8 to 10 hours to obtain a solid electrolyte membrane;

[0017] (6) A patterned electrode assembly is deposited on a solid electrolyte membrane using a one-step mask method using a radio frequency magnetron sputtering deposition system.

[0018] Application of the above-mentioned oxide transistor with temperature-sensitive color-changing function as a neuromorphic device.

[0019] Preferably, the applications include temperature sensing, neuromorphic computing and bionic color-changing electronic skin.

[0020] Preferably, the application is temperature sensing, and the neuromorphic device can be applied to biological behavior trackers, intelligent temperature monitors, and health monitors.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The oxide transistor of the present invention uses a solid electrolyte membrane formed by mixing thermochromic powder and bioelectrolyte as an insulating layer. The insulating layer is a gate dielectric layer, which can not only give play to the proton interface gate control effect of the bioelectrolyte, but also give play to the characteristic of the thermochromic powder that the color changes significantly when the temperature changes, thereby achieving obvious color changes of the oxide transistor of the present invention at different temperatures;

[0023] (2) The oxide transistor of the present invention can realize proton regulation in the electrolyte according to temperature changes, thereby realizing dynamic regulation of channel conductance. Based on the unique interface ion regulation, the oxide transistor of the present invention has good programmability and effective synaptic weight update when the temperature changes. Therefore, it can be used to simulate biological synapses, providing a novel technical method for bionic electronic skin and bionic thermochromic cognitive platform.

[0024] (3) The oxide transistor of the present invention demonstrates great advantages in neuromorphic computing and can be applied to neuromorphic devices to realize functions such as temperature sensing, neuromorphic computing, and bionic color-changing electronic skin. It has potential application prospects in the construction of green, environmentally friendly, biocompatible, and flexible wearable neuromorphic platforms and human-computer interaction platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the oxide transistor in the embodiment;

[0026] Figure 2 1 is a curve showing the variation of the channel current (Ids) of the oxide transistor with the gate-source voltage (Vgs) at different temperatures in this embodiment;

[0027] Figure 3 The excitatory postsynaptic current response of the oxide transistor in the embodiment when subjected to 0.5s pulse width electrical stimulation at different temperatures;

[0028] Figure 4 The oxide transistor in the embodiment simulates the thermal pain activity of human skin;

[0029] Figure 5 The results of MNIST handwritten digit recognition at different temperatures using a neural network constructed using oxide transistors as synapses in the embodiment;

[0030] Figure 6 The color changes of the oxide transistor array at different temperatures in the embodiment are shown. DETAILED DESCRIPTION

[0031] The present invention will be described in further detail below with reference to the accompanying drawings and examples. Unless otherwise specified, the materials used in the following examples are all commercially available products.

[0032] The oxide transistor with temperature-sensitive color change function of the embodiment, such as Figure 1 As shown, it includes a substrate 1, an oxide conductive layer 2, an insulating layer 3 and a patterned electrode assembly built in sequence from bottom to top, the substrate 1 is transparent glass, the material of the oxide conductive layer 2 is indium tin oxide, the insulating layer 3 is a solid electrolyte membrane, the electrode assembly includes a source electrode 5, a drain electrode 6 and a conductive interface 4 connecting the source electrode 5 and the drain electrode 6, the conductive interface 4 is an n-type semiconductor channel, the materials of the source electrode 5, the drain electrode 6 and the conductive interface 4 are all indium zinc oxide, and the solid electrolyte membrane is made of a mixture of thermochromic powder and chitosan in a mass ratio of 1:40.

[0033] The oxide conductive layer 2 serves as the gate of the transistor and can be regarded as the presynaptic front end, and the electrical signal stimulation applied by the gate is regarded as the presynaptic stimulation. The insulating layer 3 adopts a solid electrolyte membrane with a temperature-sensitive color change function that is insulated to electrons but conductive to protons. When an external electric field is applied to the oxide conductive layer 2, the movement of protons in the solid electrolyte membrane can be regarded as the transmission process of neurotransmitters in the synaptic cleft. When an external electric field is applied to the oxide conductive layer 2, a double layer effect is formed between the insulating layer 3, the oxide conductive layer 2, and the conductive interface 4. The source-drain current passing through the conductive interface 4 can be regarded as the synaptic weight, and the conductive interface 4 can be regarded as the postsynaptic back end.

[0034] The above-mentioned method for preparing an oxide transistor with a temperature-sensitive color-changing function comprises the following steps:

[0035] (1) A chitosan solution was obtained by a solution method: chitosan powder was dissolved in acetic acid solvent and deionized water at a mass ratio of 1:1:48 to obtain a 2 wt% chitosan solution at room temperature, and the solution was allowed to stand for 24 h to allow the chitosan powder to fully dissolve and form a uniform chitosan solution;

[0036] (2) mixing blue and red thermochromic powders with chitosan solution in a certain mass ratio, wherein the mass ratio of blue thermochromic powder to red thermochromic powder to chitosan is 1:1:80, stirring with a magnetic stirrer at room temperature, and after the two are fully mixed, using a vacuum pump to remove air bubbles to obtain a mixed solution of the two;

[0037] (3) The substrate with the oxide conductive layer was ultrasonically cleaned with alcohol for multiple times, each time for 10 minutes, and then ultrasonically cleaned with deionized water three times, each time for 10 minutes. After that, the substrate with the oxide conductive layer was blown dry with nitrogen gas, and then the substrate with the oxide conductive layer facing up was placed in a plasma cleaner for 2 minutes;

[0038] (4) using a disposable rubber-tipped dropper to absorb the mixed solution obtained in step (2), dripping the mixed solution onto the oxide conductive layer of the substrate, and uniformly coating the oxide conductive layer by drop coating;

[0039] (5) placing the substrate coated with the mixed solution on the oxide conductive layer in a drying oven and drying it at 50°C for 9.5 hours to evaporate the water in the mixed solution, thereby obtaining a solid electrolyte membrane as an insulating layer with a thickness of approximately 96 μm;

[0040] (6) Using a radio frequency magnetron sputtering deposition system, an indium zinc oxide patterned electrode assembly was deposited on a solid electrolyte membrane by a one-step mask method in a pure argon working chamber. The thickness of the source and drain electrodes in the electrode assembly was 150 nm. Due to the self-diffraction effect, a thin conductive interface was formed between the source and drain electrodes.

[0041] Figure 1 The schematic diagram of the structure of the oxide transistor with temperature-sensitive color change in the above embodiment is shown. When an electrical signal is applied to the oxide conductive layer 2 (i.e., the gate), under the influence of the external electric field, protons can use the hydroxyl groups as a pathway to continuously form and break OH bonds, resulting in a directional migration of protons. This double layer is formed at the junction of the insulating layer 3 and the conductive interface 4, which is used to regulate the conductivity of the conductive interface. Similar to the structure of a synapse, the gate acts as the front end of the synapse, and the insulating layer 3 and the conductive interface 4 act as the synaptic cleft and back end of the synapse, respectively.

[0042] Figure 2 The following curves show the variation of the channel current (Ids) of the oxide transistor as a function of the gate-source voltage (Vgs) at different temperatures in this example. The source-drain bias (i.e., gate voltage) is set at 1.5V. It can be seen that the curve exhibits counterclockwise hysteresis, which is caused by proton migration. As the temperature increases, the transfer curve exhibits a slight positive shift. As the temperature increases from 35°C to 60°C, the hysteresis window decreases from ~0.7V to ~0.5V.

[0043] Figure 3 Figure 2 shows the excitatory postsynaptic current response of the oxide transistor in the embodiment to 0.5s pulse width electrical stimulation at different temperatures. As the temperature increases from 35°C to 60°C, the peak excitatory postsynaptic current increases from 4.49μA to 16.29μA.

[0044] Figure 4The thermal pain sensation of human skin was simulated for the oxide transistor with a temperature-sensitive color change function in the embodiment. A presynaptic voltage pulse with an amplitude of 1.5V was applied to the gate of the transistor, and a test voltage of 0.5V was applied to the drain. As the temperature of the glass substrate contact gradually increased, the peak excitatory postsynaptic current also increased accordingly. Voltage pulses with widths of 0.1s, 0.5s, and 1s were applied to the gate, and the relationship between the peak excitatory postsynaptic current and temperature was measured. When the spike duration was 0.1s, the peak excitatory postsynaptic current did not change significantly with increasing temperature. When the spike duration was 0.5s, the peak excitatory postsynaptic current increased from ~4.49μA to ~16.29μA as the temperature rose from 35°C to 60°C. When the spike duration was 1 second, the peak excitatory postsynaptic current increased from ~6.68μA to ~24.56μA. Our bodies can perceive a wide range of temperatures. This perception is related to the intensity of the thermal stimulus and the duration of exposure. The stronger the thermal stimulus, the more intense the temperature perception. The critical temperature that triggers thermal pain sensations decreases as the duration of thermal stimulation increases. In this experimental test, an excitatory postsynaptic current of 16 μA was set as the threshold for thermal pain sensation. When the spike duration was 0.5 seconds, the thermal pain temperature was estimated to be ~60°C. However, when the spike duration was 1 second, the thermal pain temperature dropped to ~50°C. This behavior is similar to the temperature perception pattern of human skin.

[0045] Figure 5 The results of the neural network constructed with oxide transistors as synapses in the embodiment for recognizing MNIST handwritten digits at different temperatures are shown. The effect of the number of training times on the recognition degree of the oxide transistor with temperature-sensitive color change function at different temperatures in the embodiment is detected. Specifically, 64 positive current pulses (10nA, 10ms) and 64 negative current pulses (-5nA, 10ms) are applied successively to adjust the current synaptic weight. Between each pulse, a drain voltage pulse (0.8V, 10ms) is used to read the synaptic weight value. The time interval between applying the current pulse and reading the current pulse is 10ms. An artificial neural network is constructed using the MNIST database, and a multilayer perceptron simulation is performed for pattern recognition. After 125 times of learning and training, the recognition accuracy at different temperatures is ~93.80%, indicating that the oxide transistor with temperature-sensitive color change function in the embodiment has good stability in neuromorphic computing. Therefore, the oxide transistor with temperature-sensitive color change function of the present invention has pattern recognition function, can realize neuromorphic computing, and provides a candidate technology for constructing neural networks.

[0046] Figure 6The color change of the oxide transistor array in the embodiment within the temperature range of 35° C. to 60° C. is shown. In the temperature range of 35° C. to 60° C., obvious thermochromic behavior can be observed, with the color changing from deep red to light white.

[0047] The above examples only used blue and red thermochromic powders, resulting in relatively simple color changes. In reality, various thermochromic powders can be mixed with chitosan to adjust the color and critical thermochromic temperature. Because this oxide transistor changes color with temperature, it can be used in biomimetic cognitive electronic skin with thermochromic functionality.

[0048] Specific applications of the above-mentioned oxide transistor with temperature-sensitive color-changing function as a neuromorphic device include but are not limited to the following neuromorphic devices:

[0049] 1) Biological behavior tracker

[0050] In field biological research, humans need to closely observe and record the behavior patterns of animals in order to better understand their daily lives and habits. However, some animals are very sensitive to the presence of humans and will stay away from, avoid, or even attack them, so it is difficult for humans to observe and track them at close range. The oxide transistor with a temperature-sensitive color-changing function of the present invention is integrated into the surface of a biological habit tracker. By selecting and matching various colors of temperature-sensitive color-changing powder, the desired color is presented, so that the entire instrument surface can change color according to the ambient temperature. Without the need for additional heating devices, its appearance color changes to match the surrounding vegetation and climatic conditions, achieving a perfect camouflage effect and greatly reducing the chance of alerting animals. Through the remote control tracker, the behavioral data of the target animal is collected, and the temperature, humidity and other parameters of the surrounding environment are recorded, so as to gain an in-depth understanding of their habits and living habits. The present invention can not only provide more concealed and accurate animal behavior observation, but also reduce human interference, protect the natural habits of the target animal, and facilitate humans to have a deeper understanding of the mysteries of nature.

[0051] 2) Intelligent temperature monitor

[0052] By installing the oxide transistors with temperature-sensitive color-changing function of the present invention in different areas, real-time temperature detection can be achieved. When the temperature changes, the conductivity of the transistor changes regularly and is accompanied by significant color changes. Accordingly, different colors of temperature-sensitive color-changing powders can be selected and formulated in a certain proportion so that the color change of the transistor corresponds to the temperature range, and the color change of the transistor is matched with the temperature range, and different colors are set to correspond to different temperature intervals. For example, blue represents low temperature, green represents medium temperature, and red represents high temperature. When the temperature exceeds the set threshold, the transistor will send a warning signal to remind the user to make corresponding adjustments or take safety measures. In this way, the user can not only quickly judge the working temperature range based on the color, but also determine the precise temperature value based on the change in conductivity. In addition, the working environment can be adjusted based on the real-time information of the temperature change in the working area to ensure the quality and safety of production and work, and provide users with reliable temperature monitoring and early warning services.

[0053] 3) Health monitor

[0054] The present invention's oxide transistor with a temperature-sensitive color-changing function can be used in wearable smart health monitoring instruments or devices. When in contact with human skin, it can sense changes in body temperature. When body temperature exceeds the normal range, the transistor will issue an alert through changes in color and conductivity, prompting the individual to take timely measures to protect their health. This smart health monitoring device has a wide range of applications in the healthcare field. For example, it can be used on the elderly or patients with chronic diseases to monitor body temperature changes in real time, promptly detecting fever symptoms or signs of disease progression, and providing important monitoring data to medical staff. It can also be used on athletes or sports enthusiasts to monitor body temperature changes, helping people better understand their exercise status and avoid health problems caused by excessive or insufficient exercise, such as high or low body temperature. The present invention can also be connected to devices such as smartphones or smartwatches to provide more detailed health data analysis and reminder functions. Transistor-based health monitoring devices will provide people with more convenient and intelligent health management solutions, helping them to monitor their physical condition in real time, prevent diseases, and improve their quality of life.

Claims

1. An oxide transistor with a temperature-sensitive color change function, comprising a substrate, an oxide conductive layer, an insulating layer, and an electrode assembly constructed in sequence from bottom to top, wherein the insulating layer is a solid electrolyte membrane, the electrode assembly comprises a source electrode, a drain electrode, and a conductive interface connecting the source electrode and the drain electrode, the conductive interface being an n-type semiconductor channel, and the source electrode, the drain electrode, and the conductive interface being made of metal oxides, characterized in that: The solid electrolyte membrane is formed by mixing thermochromic powder and bioelectrolyte in a mass ratio of 1: (20-100).

2. The oxide transistor with temperature-sensitive color change function according to claim 1, characterized in that: The bioelectrolyte is chitosan.

3. The oxide transistor with temperature-sensitive color change function according to claim 1, characterized in that: The thickness of the insulating layer is 2-100 μm, the thickness of the source electrode and the drain electrode are 100-300 nm respectively, and the thickness of the conductive interface is 10-50 nm.

4. The oxide transistor with temperature-sensitive color change function according to claim 1, characterized in that: The material of the oxide conductive layer is indium zinc oxide or indium tin oxide, and the metal oxide is indium tin oxide, indium tungsten oxide, indium zinc oxide or indium gallium zinc oxide.

5. Use of the oxide transistor with temperature-sensitive color change function according to any one of claims 1 to 4 as a neuromorphic device.

6. The use according to claim 5, characterized in that The applications described include temperature sensing, neuromorphic computing, and biomimetic color-changing electronic skin.

7. The use according to claim 6, characterized in that The application is temperature sensing, and the neuromorphic device is applied to biological behavior trackers, intelligent temperature monitors, and health monitors.

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