CN-121977625-A - Polyaniline-based multi-mode thermoelectric sensor for environmental hazard and vital sign monitoring

Abstract

The invention discloses a polyaniline multi-mode thermoelectric sensor for monitoring environmental hazard and vital signs. The sensor comprises a composite thermoelectric functional layer formed by polyaniline and a carbon material, wherein the carbon material is used as a flexible conductive substrate, and polyaniline grows on the carbon material in situ in an electrochemical deposition mode to form a stable polyaniline/carbon composite structure. The self-powered temperature sensing of the environmental temperature difference is realized based on the Seebeck effect of the composite material, meanwhile, the pressure sensing function is realized by utilizing the high specific surface area of the carbon material and the resistance change characteristic caused by stress of the carbon material, and the detection of the gas and the pH environment is realized by further combining the reversible doping/dedoping behavior of polyaniline. The sensor realizes multi-parameter collaborative monitoring of temperature, pressure, chemical environment and the like in a single material system, has the characteristics of simple structure, good flexibility and self-power supply, and is suitable for the fields of complex environment monitoring and vital sign sensing.

Inventors

• CHEN MENGRAN
• Zong Pengan
• ZHOU HONGQING
• LI JIANHUA

Assignees

• 南京工业大学

Dates

Publication Date

20260505

Application Date

20251231

Claims (9)

1. 1. The polyaniline-based multi-mode thermoelectric sensor for monitoring environmental hazard and vital signs is characterized by comprising conductive polymer Polyaniline (PANI) and flexible carbon-based material, wherein the carbon-based material is at least one of single-wall carbon nanotube film, multi-wall carbon nanotube film, graphite film, graphene film or flexible carbon foam.
2. 2. The sensor of claim 1, wherein the PANI is grown on a carbon-based material by electrochemical in-situ polymerization deposition, the electrochemical system is a three-electrode system, wherein the working electrode is a carbon-based material, the counter electrode is any one of platinum, gold, glassy carbon, or a high purity carbon rod, and the reference electrode is a saturated calomel electrode or a silver/silver chloride electrode.
3. 3. The multi-modal thermoelectric sensor of claim 2 wherein the electrochemical deposition method is one of cyclic voltammetry, potentiostatic deposition, galvanostatic deposition, pulsed potentiostatic deposition, or pulsed galvanostatic deposition.
4. 4. The multimode pyroelectric sensor according to claim 3, wherein the deposition potential of the cyclic voltammetry is-0.2 v to 2.5v, the deposition potential of the constant potential deposition method is 0.05v to 2.5v, the deposition current of the constant current deposition method is 0.1mA cm -2 ~40mA cm -2 , the pulse time of the pulse deposition method is 0.1s to 10s, the deposition potential of the pulse constant potential deposition method is 0.05v to 2.5v, the deposition current of the pulse constant current deposition method is 0.1mA cm -2 ~40mA cm -2 , and the total deposition time is 20s to 1000s.
5. 5. The multi-modal thermoelectric sensor according to claim 2, wherein the concentration of aniline in the electrodeposited electrolyte is 0.1mol/L to 4.0mol/L, the concentration of the acidic solution is 0.5mol/L to 2mol/L, and the acidic solution is one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or perchloric acid.
6. 6. The multimode pyroelectric sensor according to claim 1, wherein the PANI/C composite is dried in vacuum at 30-80 ℃ for 10-180 min, preferably at 50-60 ℃ for 10-80 min after deposition.
7. 7. The multi-modal thermoelectric sensor of claim 1 wherein the sensor is connected to an external circuit by a conductive connection comprising a conductive wire or conductive tape, the conductive wire being a copper wire or silver wire, the conductive tape being a copper paste or silver paste.
8. 8. The multi-modal thermoelectric sensor of claim 1, wherein the sensor is used for environmental monitoring, including at least one of high temperature environmental monitoring, flame hazard warning, hazardous gas detection, environmental temperature differential monitoring, or pH monitoring, wherein the pH monitoring is suitable for water quality monitoring, wastewater treatment, chemical reaction processes, or environmental water pH assessment.
9. 9. The multi-modal thermoelectric sensor of claim 1, wherein the sensor is used for vital sign monitoring, including at least one of body temperature monitoring, respiration monitoring, pulse monitoring, skin contact pressure monitoring, or pH monitoring, and is applicable to a wearable device.

Description

Polyaniline-based multi-mode thermoelectric sensor for environmental hazard and vital sign monitoring Technical Field The invention belongs to the technical field of sensors, and particularly relates to a polyaniline multi-mode thermoelectric sensor for monitoring environmental hazard and vital signs. Background The existing thermoelectric sensor is mainly based on the Seebeck effect, and directly converts the temperature difference into an electric signal to realize self-powered detection. According to the material system and application form, the material system can be divided into three types, namely inorganic thermoelectric sensors, such as graphene, carbon nano tubes, bi 2Te3, pbTe, skutterudite and the like, and has the characteristics of higher thermoelectric performance (large ZT value) and good stability, but the inorganic materials are generally high in rigidity and processing difficulty, which are unfavorable for flexible or wearable application, and in addition, the low-dimensional carbon-based materials such as graphene, carbon nano tubes and the like are frequently used as conductive frameworks or functional fillers for constructing flexible thermoelectric networks and optimizing carrier transportation and interface transmission according to the characteristics of high specific surface area, high conductivity, high carrier mobility, flexible and the like. However, the material generally needs to be supported and fixed by a polymer or a matrix material in a flexible device, and a single carbon material system still has a certain limitation in terms of film forming property, mechanical integrity and multifunctional integration. The two types are organic or conductive polymer pyroelectric sensors, such as Polyaniline (PANI), polyethylene dioxythiophene/polystyrene sulfonate (PEDOT: PSS), polypyrrole (PPy) and the like, and have the advantages of flexibility, stretchability and easiness in preparation or wearable devices, wherein the polyaniline is different from other conductive polymers, the conductivity is derived from pi conjugated structures in a main chain of the polyaniline and protonation processes caused by acid doping, and the polarons/dipoles formed after doping obviously improve the carrier concentration, so that the conductivity can be continuously regulated and controlled in a wide range. The conductive state of the PANI can be accurately regulated through a reversible doping-dedoping process, meanwhile, the good environmental stability is kept, the PANI has unique advantages in a flexible and thermoelectric device, but the overall thermoelectric performance is still relatively limited, and three types are composite material thermoelectric sensors, and the high polymer and inorganic materials are compounded to enhance the conductivity and the thermoelectric performance while keeping the flexibility, so that the PANI is suitable for flexible electronic and wearable monitoring scenes. Although pyroelectric sensors can respond to temperature differential changes, in complex applications, it is difficult for a single pyroelectric signal to fully reflect physiological or environmental conditions. For example, in wearable health monitoring, detecting body surface temperature alone does not provide information such as expression, movement, or heart. Meanwhile, modern rescue works face more dangerous environments, and the sensor needs to have the capability of detecting various parameters such as gas, pH and the like. For this reason, the development of multi-modal sensors has become a trend. Through integrating multiple sensing functions, the sensors not only can fuse multiple signals and improve the function integration level, but also can keep flexibility, wearability and self-powered characteristics, enhance monitoring precision and application range, and promote the intelligent sensor to develop to high performance and multi-mode directions. Disclosure of Invention Aiming at the technical problems that the existing thermoelectric sensor can effectively detect temperature difference change, most sensors still mainly rely on single function and multi-dimensional information is difficult to acquire at the same time, one of the purposes is to provide an innovative preparation method of the multi-mode thermoelectric sensor, and the real-time monitoring of chemical threat, environmental temperature and vital signs is realized by integrating multiple sensing functions on a single material. The polyaniline-based multi-mode thermoelectric sensor for monitoring environmental hazard and vital signs is characterized in that the sensor material consists of conductive polymer Polyaniline (PANI) and flexible carbon (C) materials. Preferably, the flexible carbon material is selected from one of a single-walled carbon nanotube film, a multi-walled carbon nanotube film, a graphite film, a graphene film and related flexible carbon foam. Preferably, the PANI is grown on a carbon-based material by electroch