Bioinspired Omnidirectional Iontronic Sensors Based on Triboelectric Charge.

Flexible pressure sensors are critical components in next-generation wearable electronics and intelligent human-machine interface (HMI). However, conventional designs often suffer from limited sensitivity and uniaxial force detection, restricting their applicability in complex environments. Here, a bioinspired omnidirectional iontronic sensor (BOIS) is presented, engineered via triboelectric coupling and featuring a cross-scale architecture inspired by the spatial encoding properties of cochlear cilia. Through the integration of a 70° inclined macroscopic ciliary array based on Fibonacci helix optimization and 3D printing technology, the sensor achieves high-resolution detection of both normal and shear forces. The incorporation of iontronic effects further enhances sensitivity via synergistic charge modulation. The resulting flexible sensing platform demonstrates excellent mechanical compliance, multi-axis responsiveness, and high precision in monitoring dynamic joint motions such as wrist bending and finger flexion. This work offers a robust strategy for advancing omnidirectional tactile sensing, with promising applications in medical rehabilitation, soft robotics, and HMI.