Sensitive pressure sensors based on conductive microstructured air-gap gates and two-dimensional semiconductor transistors

Microscopic pressure sensors that can rapidly detect small pressure variations are of value in robotic technologies, human–machine interfaces, artificial intelligence and health monitoring devices. However, both capacitive and transistor-based pressure sensors have limitations in terms of sensitivity, response speed, stability and power consumption. Here we show that highly sensitive pressure sensors can be created by integrating a conductive microstructured air-gap gate with two-dimensional semiconductor transistors. The air-gap gate can be used to create capacitor-based sensors that have tunable sensitivity and pressure-sensing range, exhibiting an average sensitivity of 44 kPa⁻¹ in the 0–5 kPa regime and a peak sensitivity up to 770 kPa⁻¹. Furthermore, by employing the air-gap gate as a pressure-sensitive gate for two-dimensional semiconductor transistors, the pressure sensitivity of the device can be amplified to ~10³–10⁷ kPa⁻¹ at an optimized pressure regime of ~1.5 kPa. Our sensors also offer fast response speeds, low power consumption, low minimum pressure detection limits and excellent stability. We illustrate their capabilities by using them to perform static pressure mapping, real-time human pulse wave measurements, sound wave detection and remote pressure monitoring.