Integrated temperature and pressure dual-mode sensors based on elastic PDMS foams decorated with thermoelectric PEDOT:PSS and carbon nanotubes for human energy harvesting and electronic-skin

Abstract

Conventional temperature–pressure bifunctional sensors based on thermoresistive and piezoresistive effects could not meet the growing demand for detecting multiple signals due to their intractable signal-coupling problems. It is imperative to develop new approaches to detect multiple stimuli with single devices without complex decoupling processes. Herein, integrated temperature and pressure dual-mode sensors are fabricated by decorating elastic polydopamine-modified PDMS (PDA@PDMS) foam with thermoelectric PEDOT:PSS/carbon nanotube (CNT) components. The resultant PEDOT:PSS/CNT@PDA@PDMS (PCPP) sensor exhibits an accurate temperature sensing capability with an ultrahigh Seebeck coefficient of 40.5 μV K⁻¹ and an ultralow detectable temperature of 0.05 K. Thanks to the elastic and porous PDMS foam and the thermoelectric PEDOT:PSS/CNT components, the PCPP sensor can detect both static and dynamic pressures with high sensitivity, fast response time, a wide detection range, and excellent durability. Notably, under the simultaneous stimulation of both temperature and pressure, the dual-mode PCPP sensor can convert these two stimuli to independent voltage and resistance signals on the basis of thermoelectric and piezoresistive effects. Meanwhile, the thermoelectric effect endows the sensor with human energy harvesting capacity by exploiting the temperature gradients between human skin and the environment. All these characteristics make the dual-mode PCPP sensor promising for wearable electronic skin applications.