Optimization of PEDOT:PSS Aqueous Solution for High-Performance Flexible Temperature Sensors

Poly(3,4-ethylenedioxythiophene):poly(styrene- sulfonate) (PEDOT:PSS) has great potential in high-performance flexible temperature sensors for healthcare, environmental monitoring, intelligent robots, and so on. However, it is rare to study the influence of synthesis parameters of PEDOT:PSS aqueous solution on the perfor- mance of temperature sensors. In this work, we synthesized PEDOT:PSS aqueous solutions via chemical oxidative polymerization and employed them to make flexible tempera- ture sensors. By optimizing the synthesis parameters, including 3,4-ethylenedioxythiophene (EDOT) concentration, PSS:EDOT mass ratio, Na2S2O8:EDOT mass ratio, polymerization time, and substrate type, the high-performance flexible temperature sensor was successfully fabricated. The sensor exhibits an impressive sensitivity of −1.36%/°C and an excellent linearity of 0.993 in the temperature range of $28~^{\circ }$ C– $60~^{\circ }$ C. Moreover, the sensor also possesses a high-temperature resolution of $0.2~^{\circ }$ C, fast response and recovery time of 4.2 and 7.0 s, and excellent flexibility. The optimized PEDOT:PSS aqueous solution can be used to fabricate high-performance flexible sensors.