Ultralow voltage operation and microwatt power consumption of MXene-based pressure sensors with excellent sensing performance†

Abstract

Nowadays, smart flexible and wearable electronic devices are experiencing rapid development. As one of the core components, flexible pressure sensors have attracted significant attention. High sensitivity, broad detection range and fast response of the pressure sensor with low power consumption are urgently needed for various practical applications; however, it remains a great challenge to simultaneously achieve these merits. Herein, a periodically structured MXene/PDMS composite was explored to construct a high-performance, flexible piezoresistive sensor. The developed sensor had ultrahigh sensitivity (70.6 kPa⁻¹), fast response (18 ms), broad detection range (up to 436 kPa) as well as outstanding long-term stability (9700 cycles). Moreover, the sensor showed a low operation voltage (0.01 V) and low power consumption (max. 120 μW), and it was successfully powered by a thermoelectric generator using a tiny temperature difference between the human skin and environment. We also combined the sensor with an artificial neural network model and realized a high accuracy recognition (97%) of the Morse code. These results indicate that periodically structured MXene/PDMS sensors hold great potential in practical applications such as human motion monitoring, robotic control and encrypted communication. Additionally, this work presents a new approach for the development of highly sensitive, broad-range-response, and multifunctional self-powered energy-saving wearable electronics.