A flexible and ultrasensitive interfacial iontronic multisensory sensor with an array of unique “cup-shaped” microcolumns for detecting pressure and temperature

Abstract

Flexible sensors with high-performance pressure and temperature sensing capabilities are highly desirable due to their widespread applications in electronic skins and wearable electronics. Utilizing the transition state between Cassie−Baxter state and Wenzel state during the surface coating on silicon template, we designed a dielectric layer with arrayed “cup-shaped” microcolumns composed of thermoplastic polyurethane (TPU) and ionic liquids (ILs), which was further applied to assemble with two flexible silver nanowires (AgNWs)/polydimethylsiloxane (PDMS)-based electrodes to form a flexible iontronic multisensory sensor with the electric double layer (EDL) generated at the interface between electrode and dielectric layer. As a pressure sensor, a high sensitivity of 87.75 kPa−1, wide detection range up to 170 kPa, high resolution of 0.22 Pa, and fast response/recovery time of 7.52/13.97 ms are achieved due to the formation of interfacial EDL and the unique structural evolution of the arrayed TPU/ILs cup-shaped microcolumns upon pressure. In addition, the as-prepared sensor also exhibits extraordinary temperature sensing performance, including a high resolution of 0.1 °C, high sensitivity of 52.77% °C−1, and wide detection range from − 40 to 90 °C, owing to the dependence of the dielectric constant of TPU/ILs layer on temperature. Attributed to these excellent sensing capabilities, our sensor possesses great potential in soft robotics, prosthetic prosthetics, and medical monitoring systems.