A Graphene-Based Resistive Pressure Sensor with Record-High Sensitivity in a Wide Pressure Range

TLDR

Pressure sensors are essential for electronic skin, but most resistive types lose sensitivity above 5 kPa, limiting their use across the 0–100 kPa range required for gentle touch and object manipulation. This study aims to demonstrate a flexible, wide‑range, ultra‑sensitive resistive pressure sensor based on laser‑scribed graphene. The sensor employs a foam‑like laser‑scribed graphene structure with large interlayer spacing and a v‑shaped microstructure to achieve high sensitivity. The resulting sensor achieves a record 0.96 kPa⁻¹ sensitivity over 0–50 kPa, outperforms all prior reports, and its behavior is accurately predicted by a validated model, indicating suitability for e‑skin, medical, and biosensing.

Abstract

Abstract Pressure sensors are a key component in electronic skin (e-skin) sensing systems. Most reported resistive pressure sensors have a high sensitivity at low pressures (<5 kPa) to enable ultra-sensitive detection. However, the sensitivity drops significantly at high pressures (>5 kPa), which is inadequate for practical applications. For example, actions like a gentle touch and object manipulation have pressures below 10 kPa and 10–100 kPa, respectively. Maintaining a high sensitivity in a wide pressure range is in great demand. Here, a flexible, wide range and ultra-sensitive resistive pressure sensor with a foam-like structure based on laser-scribed graphene (LSG) is demonstrated. Benefitting from the large spacing between graphene layers and the unique v-shaped microstructure of the LSG, the sensitivity of the pressure sensor is as high as 0.96 kPa −1 in a wide pressure range (0 ~ 50 kPa). Considering both sensitivity and pressure sensing range, the pressure sensor developed in this work is the best among all reported pressure sensors to date. A model of the LSG pressure sensor is also established, which agrees well with the experimental results. This work indicates that laser scribed flexible graphene pressure sensors could be widely used for artificial e-skin, medical-sensing, bio-sensing and many other areas.