Atomically Suspended Graphene/MoS2 Heterojunction Driven High-Resolution Air Pressure Sensor for Fall Detection.

Air pressure sensors are widely used in aerospace, the military, and healthcare. The core metrics (sensitivity and resolution) of sensors are being driven to increasingly higher standards by expanding application demands such as in wearable devices. Reducing the device size while maintaining or even improving sensor performance remains one of the key challenges in the field. We present a high-sensitivity, high-resolution air pressure sensor based on an atomically suspended graphene/MoS2 heterojunction. After structural optimization, the air pressure sensor achieves a sensitivity of 0.152 kPa-1 and resolution of 5 Pa within a compact sensing area of 78.5 μm2, which is over 2 orders of magnitude better than previous graphene- or silicon-based sensors. The normalized sensitivity (∼0.0019 kPa-1μm-2) supported miniaturization of wearable systems. Finally, an integrated wrist-worn prototype demonstrated highly sensitive and reliable human fall detection. Our research highlights the feasibility of using air pressure sensors for human fall monitoring in the future.