Bioinspired Design of Hill‐Ridge Architecture‐Based Iontronic Sensor with High Sensibility and Piecewise Linearity

Abstract Iontronic sensing has experienced a rapid growth in recent years due to its ultrahigh device sensitivity, high resolution, and high spatial definition. However, most of the reported sensors usually exhibit a highly nonlinear response for the dramatic drop of sensitivity as pressure increasing. Here, a sensitive, piecewise linear flexible iontronic pressure sensor is reported. Inspired by the relationship between microstructure of fly mechanoreceptors and their associated stimuli, hill‐ridge architecture (HRA)‐based sensors with piecewise high sensitivity and linearity are designed and successfully prepared by using a simple and adjustable PDMS prestretched template. The developed sensor demonstrates a high sensitivity of 37.7 kPa^–1 in the low‐pressure range (0–4 kPa) and 4.69 kPa^–1 in higher load force (100–350 kPa). It is worth emphasizing that the response in both loading ranges is linear. Besides, the sensor exhibits a short dynamic response time of 23 ms together with extremely low LOD of 0.32 Pa and remarkable mechanical stability (>5000 cycles). Finally, the applications of the sensor for artery pulse detection, handwriting identification, and spatial discrimination are demonstrated. Benefiting from the unique properties, the proposed sensor can be advantageous for the potential applications in fields of motion detection, healthcare monitoring, and human‐machine interfaces.