Flexible, Low-Cost, and High-Performance Capacitive Pressure Sensor Enabled by Combining Double-Sided Microstructured Electrodes with a Single Soft Dielectric Layer

To address the trade-off between high sensitivity and wide linear detection range, as well as the fabrication complexity and mechanical instability of traditional microstructure engineering in flexible capacitive pressure sensors, this work constructs a flexible, low-cost, and high-performance capacitive pressure sensor enabled by double-sided microstructured electrodes combined with a single soft dielectric layer derived from a nitrile protective glove. The results show that the proposed flexible capacitive pressure sensor has a wide pressure detection range of 0.1–180 kPa with sensitivities of 0.95 kPa–1 (0–30 kPa) and 0.13 kPa–1 (30–180 kPa). In addition, it exhibits a low detection limit of approximately 2.5 Pa, negligible drift after 5000 loading–unloading cycles at 10 kPa, and good batch consistency. The pressure sensing mechanism is elucidated based on the changes in microstructure morphology and finite element analysis results. The proposed flexible capacitive pressure sensor is finally demonstrated for various applications such as step counting, Morse code generation, wrist pulse, and respiratory pattern discrimination. This work provides a simple and low-cost approach for fabricating high-performance flexible capacitive pressure sensors.