Fingerprint-Inspired High Conductive PEDOT-Coated Nanofiber Film for Ultra-Sensitive, Stretchable, and Flexible Piezoresistive Sensor

Flexible piezoresistive sensors are extensively applied in smart health monitoring systems due to their excellent shape adaptability, portability, and comfortableness. However, constructing piezoresistive sensors with both high sensitivities and wide pressure range remains a huge challenge. In this paper, inspired by the fingerprint structure, a 3D poly (3,4-ethylenedioxythiophene) coated wrinkled nanofiber film based flexible piezoresistive sensor is developed through a simple method. Benefiting from the undulating structure of the conductive nanofiber film, there are abundant micro-ridges on the surface of the rough nanofiber network, which make a significant contribution to the construction of new conductive paths under different pressures. This assembled sensor exhibits an ultra-high sensitivity of 397.54 kPa(-1) in a small pressure range (0-3 kPa) as well as an ultra-wide pressure range of 0-25.48 kPa. In addition, it can maintain stable signal output even after 16 500 compression cycles. Furthermore, this high-performance piezoresistive sensor is demonstrated to accurately identify the wrist pulse and joint bending of human body, which enables an extensive application prospect in the field of wearable electronics.