Charge-defect tuned PVDF based ternary biocompatible composite as skin touch actuated single electrode triboelectric nanogenerator for wireless healthcare monitoring

Abstract

Here, PVDF/ZnO/Ag (PVDF – poly(vinylidene fluoride)) based ternary biocompatible composites with the unique feature of improved conductivity have been developed which have enabled enhanced energy harvesting performance. A single-electrode triboelectric mechanism has been used here to use the films directly on the human body (as they are biocompatible). The optimized piezoelectric nanogenerator (PENG) device has shown a very high output with ∼28 V of open-circuit voltage (VOC), 1.2 μA of short-circuit current (ISC), and 17 μW/cm2 of power density. On the other hand, the optimized single electrode triboelectric nanogenerator (SETENG) device has been found to show ∼175 V of VOC, 21 μA of ISC, and 170 μW/cm2 of power density. The enhanced output performance has been correlated with improved polarity, enhanced charge-defects, and improved tribo-negativity of the composites caused by Ag addition. Due to this high output, both the PENGs and SETENGs have been used here for different real-life applications including pressure sensing, vibration sensing, touch sensing, and powering small electronics. The biocompatibility of the films and the unique design of SETENGs with wireless activity have enabled them to harvest electricity from body movement and sense body movement, which was very advantageous for healthcare monitoring and phonation monitoring purposes.