Laser-assisted micropyramid patterned PDMS encapsulation of 1D tellurium nanowires on cellulose paper for highly sensitive strain sensor and its photodetection studies

This work demonstrates the fabrication of tellurium-nanowires (Te-NWs)/paper based device encapsulated using laser assisted mircopyramid patterned polydimethylsiloxane (PDMS) films. Although there are multiple reports published on 1D Te, most of them are limited to establishing its properties and studying its behavior as a sensor and research on the utilization of Te-NWs for physical sensors remain unexplored. Further, reports on p-type photodetectors also remain scarce. The fabricated Te-NWs/paper with micropyramid structured PDMS films encapsulation was used as a strain sensor, and it exhibited considerable improvement (similar to 60%) in sensitivity compared to smooth PDMS films. The gauge factor of the developed strain sensor was found to be similar to 15.3. In addition, fabricated Te-NWs/paper device with contacts was used as a photodetector and it showed photoresponsivity of similar to 22.5 mA W-1 and similar to 14.5 mA W-1 in visible and NIR regions, respectively. Furthermore, the device exhibited long-term mechanical stability under harsh deformations. Fabricated 1D Te-NWs/paper device was utilized as a strain sensor to monitor the angular movements in the human body and successfully monitored various human motions, including wrist bending, finger knuckle, elbow joint, and knee joint. The successful demonstration of Te-NWs based physical sensors and utilization in broadband photodetectors opens avenues of research for tellurium based flexible and wearable devices.