Understanding the Roles of Microstructure and Viscoelasticity of Soft Ionic Elastomer for Super-Capacitive Pressure Sensors.

Soft ionic conductive elastomers offer unique advantages for super-capacitive pressure sensors, where the electrical double layer (EDL) effect enables high sensitivity and rapid response. However, the roles of microstructure and viscoelasticity on EDL-driven sensing remain poorly understood. This study establishes detailed correlations between elastomer microstructure, intrinsic viscoelastic properties, and sensor performance by integrating mechanical and electrical analyses. Validation of the EDL mechanism reveals how microstructural optimization and viscoelastic tuning enhance sensitivity, linear range, and stability. Height-graded architectures yield a sensor with a sensitivity of 2.70 nF/kPa, a broad linear range of 0-2000 kPa, and robust durability over 10 000 cycles. These devices demonstrate multifunctionality in robotic electronic skin, pressure mapping, and real-time physiological monitoring such as wrist pulse detection. The findings establish key structure-property-performance relationships, providing design guidelines for next-generation, high-performance super-capacitive sensors.