Flexible and breathable all-nanofiber iontronic pressure sensors with ultraviolet shielding and antibacterial performances for wearable electronics

Abstract

Fabricating flexible pressure sensors with comprehensive performances is highly desired but is still a critical challenge up to now. Herein, we present a breathable and flexible all-nanofiber iontronic pressure sensor with various merits of high-pressure sensitivity, excellent ultraviolet (UV)-shielding, self-cleaning, and antibacterial performances. The fabricated pressure sensor is assembled by three layers of breathable electrospun thermoplastic polyurethane (TPU) nanofiber films. The inner layer, which is constructed by TPU nanofibers loaded with ionic liquid, offers free ions to enhance the capacitance intensity because of the formation of interfacial electric double layer, thus increasing the pressure sensitivity of the sensor. The as-prepared iontronic flexible pressure sensor exhibits a high sensitivity of 6.21 kPa−1, wide working range from 23 Pa to 120 kPa, fast response time of 170 ms and recovery time of 135 ms, and excellent stability over 6000 loading/unloading cycles. More interestingly, nano-TiO2 is filled in the TPU nanofibers of the two outer layers, endowing the pressure sensors with excellent UV-shielding, self-cleaning, and antibacterial performances, which are the ideal merits for wearable electronics. By virtue of these remarkable performances, the sensor could be employed in human psychological signal monitoring and wearable encrypted information transmission system, exhibiting great potential in wearable electronics.