A Bioinspired Hierarchical Microstructure for Iontronic Pressure Sensors with an Ultrawide Range for Gesture Recognition

Flexible pressure sensors are inherently limited by a fundamental trade-off between the sensitivity and detection range. Although iontronic pressure sensors (IPSs) exhibit superior sensitivity, they often encounter signal saturation under high-pressure conditions, thereby limiting their operational scope. In this study, we propose a bioinspired IPS that overcomes this limitation by incorporating a hierarchical microstructure inspired by a strawberry. The design features stiff achene-like protrusions integrated onto a compliant, mountain ridge-like architecture, which facilitates a sequential deformation mechanism. As a result, the sensor achieves both an exceptionally wide detection range (0–3.57 MPa) and high sensitivity across multiple linear response intervals (445.2 kPa –1 at 0–250 and 188.4 kPa –1 at 250–3570 kPa). Additionally, the device demonstrates excellent durability (>6000 cycles) at 976.1 kPa and a fast response time. Its functional applicability is demonstrated through a sensor-integrated glove, which, when integrated with a network, achieves 94% accuracy in recognizing 26 distinct sign language gestures. This work establishes a design framework for the development of high-performance flexible electronic systems capable of effectively responding to a wide range of mechanical stimuli, from subtle tactile inputs to intense mechanical impacts.