Facile patterning of hierarchical ionic microstructures for a pressure-sensitive ionic capacitive interface

Abstract

The emulation of human tactile perception is pivotal in advancing electronic skin technologies, necessitating pressure sensors with wide dynamic range capabilities. Conventional approaches relying on multilayered architectures yield bulky devices that resist miniaturization, particularly problematic for users with foreign body sensitivity. Here, we present a pressure-sensitive ionic capacitive interface (PSICI) with hierarchical microstructures by employing an iontronic sensing mechanism, demonstrating enhanced low-pressure sensitivity sufficient for detecting subtle physiological signals such as radial artery pulsations. A conformal sensor array engineered for curved surfaces enables spatially resolved pressure mapping on anatomical geometries. PSICI's seamless epidermal integration improves human–device interfacial fidelity through sensitive tactile feedback. Proof-of-concept demonstrations in joint motion monitoring illustrate its versatility across various wearable applications, including healthcare diagnostics, virtual reality systems, and intelligent wearables. The architecture's intrinsic simplicity and reliability position the PSICI as a promising platform for scalable epidermal electronics.