Triboelectric energy harvester for controlled transdermal drug delivery and healthcare applications

In recent years, many kinds of triboelectric nanogenerators (TENG) based on the conjunction of triboelectrification and electrostatic effects have been developed and demonstrated for various energy related applications. Because of its simple structure and facile fabrication craft, TENG can be easily miniaturized to act as a mechanical sensor for detecting vibration, wind speed, location, heart beating, and so forth from various mechanical sources. By leveraging the MEMs technology and flexible materials fabrication processes, we developed various TENGs aiming different medical applications. Technology for enabling drug delivery with precise control is strongly demanded by patients with diabetes or other chronic diseases. More intelligent functions such as drug loading and delivery in controllable manner without requiring electrical power will make low-cost drug delivery patches come true. A smart microneedle patch is developed with the integration of microneedle patch and TENGs for a volume controlled drug delivery triggered by finger pressing. Leveraging triboelectric materials and compatible fabrication technology, we successfully develop a self-powered flexible skin patch for transdermal insulin delivery with novel liquid volume sensor to monitor delivered drug volume and flexible energy harvester using the same triboelectric mechanism. We also explore the feasibility of direct neural stimulation by the output signal from TENGs. With a unique design of water/air triboelectric nanogenerator (WATENG), the charge transfer during the operation of WATENG can be amplified to direct stimulate tibials nerve and peroneal nerve and induce plantar flexion and ankle dorsiflexion. Meanwhile, the WATENG connected with a sling electrode wrapped around the sciatic nerve can also realize a selective stimulation.