Highly Responsive Asymmetric Pressure Sensor Based on MXene/Reduced Graphene Oxide Nanocomposite Fabricated by Laser Scribing Technique

Abstract

Flexible pressure sensors play a vital role in wearable devices, human physiological activity monitoring, smart robots and other fields. However, current flexible piezoresistive sensors typically have the disadvantages of complex preparation processes, inability to take into account sensitivity and pressure response range, and poor cycle stability. Herein, a novel flexible asymmetric pressure sensor has been proposed by adjusting sensing material and optimizing the structure of electrode. As a crucial piezoresistive material, MXene/reduced graphene oxide (MXene/rGO) nanocomposite with a layer by layer stacked structure is developed by an efficient and precise one-step laser scribing technology. Benefit from this designed layer by layer crosslinked structure, the proposed flexible MXene/rGO asymmetric pressure sensor exhibits excellent pressure-sensing performances, such as high sensitivity of 2.25 kPa^&#x2212;1 (0 &#x2013; 200 Pa), low detection limit of about 2.5 Pa, fast responsive recovery, and long cycle durability. So that our flexible MXene/rGO asymmetric pressure sensor can detect subtle body physiological motions in real time, such as wrist pulse, vocal vibration, finger movement, and breath. Additionally, the as-prepared sensor array integrated by <inline-formula> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> identical MXene/rGO asymmetric pressure sensors exhibits good multi-touch function. Therefore, such conspicuous sensing performances endow our MXene/rGO asymmetric pressure sensor for widespread practical applications in future flexible wearable electronics.