Large area deposition of Janus MoS2x Se2(x−1) on paper as a multifunctional electromechanical sensor for versatile physiological signal monitoring

Abstract

The recent advancements in smart materials, processing techniques, and sensing technology have pervasive to the development of the modern era of flexible electronic systems. Flexible pressure and strain sensors with multi-functional sensing capabilities have gained significant interest as they have potential applications in human motion detection, physiological signal monitoring, flexible robotics, electronic skin, and smart displays. Hence this puts forward a higher requirement to develop highly sensitive, low cost and high-performance electromechanical sensors. Herein, we demonstrate the fabrication of solution-processed MoSSe/paper-based flexible Pressure and strain sensor with PDMS encapsulation using facile hydrothermal and vacuum filtration method with merits of low cost, large-area deposition, high scalability, and superior sensing performance. The fabricated device exhibited a very high sensitivity of 108.09 kPa−1 and a gauge factor of 27.57 with good reproducibility, stability, and resilience for 1200 bending cycles which indicates the robustness of the device. The enhanced sensing efficiency can be accounted for the excellent piezoelectric property and the pressure, strain-induced bandgap modulation observed in Janus MoSSe which arises due to the loss of symmetry in the crystal lattice. The sensors were utilized for real-time applications for the detection of various human physiological signals by integrating them into body parts, breath sensing, handwriting recognition, unknown shape detection, and pressure mapping. This successful demonstration of high performance, low cost, and large area deposited paper-based pressure and strain sensors, opens up new opportunities for far-reaching applications in health care, security, smart systems, and robotics.