Research On Flexible Temperature Sensor Based On Nanocomposite

In recent years,with the rapid development of big data and wearable smart terminals,sensors as one of the core devices are being widely used in electronic skins,intelligent robots and functional devices,and gradually impact on the traditional healthcare industry,catering industry and agriculture.Based on the advantages of excellent sensing function of flexible electronic sensors?mechanics,temperature,heart rate,blood pressure,etc.?,good biocompatibility,lightweight and low power consumption,it has become the key research orientation in the electronics industry and of the related scientific research fields.There are few researches on flexible temperature sensors in the field of flexible electronics.How to introduce conductive composite materials into organic polymer materials with high tensile properties and strain adaptability so that they can have the temperature-sensitive performance of traditional temperature sensors is the key problem in the research of flexible temperature sensors.In this paper,two new types of flexible temperature sensors are proposed.The theoretical model,fabrication process,temperature sensitivity and related applications of the sensors are studying respectively.The thesis includes the following specific contents:?1?Experimental research based on PVA flexible temperature sensor.MWCNT was selected as the main filling material,the ratio of MWCNT/NTC material was changed by adding different NTC thermistor materials(CaCu₃Ti₄O₁₂?CCTO?,SnO₂,CoO,MnO),and PVA was used as the base material.Finally,the mixed colloid was p by solvent dispersion method.The PVA flexible temperature-sensitive device was fashioned by the mixed colloid through the automatic spin coating process,and the test results showed that:The PVA sensor with MWCNT/MnO mass ratio of 1:1 has the largest resistance change in the temperature range of 40¹20?,and the temperature coefficient of resistance?TCR?is as high as-0.0094?^-1.The PVA sensor with MWCNT/CCTO mass ratio of 10?1 had the optimal linear change in the temperature range of 40¹20?,and the linearity was as high as 99.97%.The PVA sensor has a little flexibility and shows good temperature sensitivity in breath test,light response and other application scenarios.?2?PDMS flexible temperature sensor with high sensitivity.PDMS was selected as the substrate and MWCNT/NTC material was used as the temperature sensitive unit to prepare PDMS/MWCNT/NTC composite temperature sensitive colloid.Finally,the corresponding curing agent was selected and the PDMS flexible temperature sensitive device was prepared by rotating coating on the substrate.Finally,the corresponding curing agent was selected and the PDMS flexible temperature sensitive device was prepared by spinning on the substrate.The test results showed that the PDMS fabric made of MWCNT/CCTO had good temperature sensitivity and linearity at-40¹20?,the resistance change was-63.59%,TCR was-0.0094?^-1,and the linearity was up to99.83%.In addition,the sensor maintained good stability after 500 repeatability tests,5000 consecutive tensile tests and 3000 consecutive pressure tests.Based on the good temperature sensitivity and stability of the PDMS flexible temperature sensitive device,the device also exhibits excellent sensing performance in the practical environmental test of human respiration monitoring,light response and water temperature response.