Micropatterned Pyramidal Ionic Gels for Sensing Broad-Range Pressures with High Sensitivity

TLDR

Broad‑range pressure sensors are essential for future electronic skin capable of detecting pressures from acoustic waves to dynamic human motion. The study presents flexible capacitive pressure sensors that use micropatterned pyramidal ionic gels for ultrasensitive pressure detection. These sensors employ high‑dielectric‑constant ionic gels in a metal‑insulator‑metal capacitive structure. They achieve a sensing range from a few pascals to 50 kPa, respond in <20 ms, operate at 0.25 V, and reach a low‑pressure sensitivity of 41 kPa⁻¹, enabling detection of sound waves, light objects, jugular and radial pulses, and finger touch.

Abstract

The development of pressure sensors that are effective over a broad range of pressures is crucial for the future development of electronic skin applicable to the detection of a wide pressure range from acoustic wave to dynamic human motion. Here, we present flexible capacitive pressure sensors that incorporate micropatterned pyramidal ionic gels to enable ultrasensitive pressure detection. Our devices show superior pressure-sensing performance, with a broad sensing range from a few pascals up to 50 kPa, with fast response times of <20 ms and a low operating voltage of 0.25 V. Since high-dielectric-constant ionic gels were employed as constituent sensing materials, an unprecedented sensitivity of 41 kPa-1 in the low-pressure regime of <400 Pa could be realized in the context of a metal-insulator-metal platform. This broad-range capacitive pressure sensor allows for the efficient detection of pressure from a variety of sources, including sound waves, a lightweight object, jugular venous pulses, radial artery pulses, and human finger touch. This platform offers a simple, robust approach to low-cost, scalable device design, enabling practical applications of electronic skin.