Graded intrafillable architecture-based iontronic pressure sensor with ultra-broad-range high sensitivity

TLDR

Sensitivity is a key parameter for flexible pressure sensors, yet micro‑pyramid structures that enhance sensitivity also limit the pressure‑response range due to poor compressibility. The authors propose engineering intrafillable microstructures to simultaneously increase sensitivity and broaden the pressure‑response range, a design that can be applied to other sensors. These intrafillable microstructures incorporate undercuts and grooves that accommodate deformed surface features, thereby improving structural compressibility and extending the pressure‑response range. The resulting iontronic sensor achieves an unprecedented sensitivity of >220 kPa⁻¹ across 0.08 Pa–360 kPa, an ultrahigh resolution of 18 Pa (0.0056 %), and excellent mechanical stability.

Abstract

Abstract Sensitivity is a crucial parameter for flexible pressure sensors and electronic skins. While introducing microstructures (e.g., micro-pyramids) can effectively improve the sensitivity, it in turn leads to a limited pressure-response range due to the poor structural compressibility. Here, we report a strategy of engineering intrafillable microstructures that can significantly boost the sensitivity while simultaneously broadening the pressure responding range. Such intrafillable microstructures feature undercuts and grooves that accommodate deformed surface microstructures, effectively enhancing the structural compressibility and the pressure-response range. The intrafillable iontronic sensor exhibits an unprecedentedly high sensitivity ( S min > 220 kPa −1 ) over a broad pressure regime (0.08 Pa-360 kPa), and an ultrahigh pressure resolution (18 Pa or 0.0056%) over the full pressure range, together with remarkable mechanical stability. The intrafillable structure is a general design expected to be applied to other types of sensors to achieve a broader pressure-response range and a higher sensitivity.