2D PtSe Enabled Wireless Wearable Gas Monitoring Circuits with Distinctive Strain-Enhanced Performance.

The application of 2D materials-based flexible electronics in wearable scenarios is limited due to performance degradation under strain fields. In contrast to its negative role in existing transistors or sensors, herein, we discover a positive effect of strain to the ammonia detection in 2D PtSe. Linear modulation of sensitivity is achieved in flexible 2D PtSe sensors via a customized probe station with an in situ strain loading apparatus. For trace ammonia absorption, a 300% enhancement in room-temperature sensitivity (31.67% ppm) and an ultralow limit of detection (50 ppb) are observed under 1/4 mm curvature strain. We identify three types of strain-sensitive adsorption sites in layered PtSe and pinpoint that basal-plane lattice distortion contributes to better sensing performance resulting from reduced absorption energy and larger charge transfer density. Furthermore, we demonstrate state-of-the-art 2D PtSe-based wireless wearable integrated circuits, which allow real-time gas sensing data acquisition, processing, and transmission through a Bluetooth module to user terminals. The circuits exhibit a wide detection range with a maximum sensitivity value of 0.026 V·ppm and a low energy consumption below 2 mW.