A Flexible Iontronic Pressure Sensor With High Sensitivity and Fast Response Enabled by a Bio‐Inspired Contact‐Area‐Amplifying Microstructure

ABSTRACT Advancements in flexible pressure sensors have been substantial. However, traditional configurations are restricted in pressure‑response scope owing to structural stiffening. Inspired by biological structures, we present an iontronic flexible pressure sensor featuring a microstructured electrode to amplify contact area variation under pressure. This architecture enhances the device's deformability while minimizing initial contact area, leading to high sensitivity. In addition, the sensor employs a composite ionic dielectric layer composed of polyvinyl alcohol and [BMIM]BF 4 , thereby enhancing ion transport efficiency, and silver nanowires serve as the conductive electrode component to maintain reliable electrical conduction during mechanical deformation. In the operational range of 0–335 kPa, the device demonstrates a highest sensitivity of 10.856 ± 0.114 kPa −1 , coupled with a response duration of 62.5 ± 8.3 ms and a recovery period of 75 ± 10.2 ms, as supported by experimental measurements. After 3000 consecutive cycles under external loads of 2.5 and 250 kPa, the sensor showed no significant signal attenuation, indicating its excellent mechanical durability. In wearable applications, this sensor reliably detects gestures and sign language through capacitive sensing, thanks to its highly repeatable performance and stable dynamic response, demonstrating great potential for use in motion detection.