Elastic and Skin-Contact Triboelectric Nanogenerators\nand Their Applicability in Energy Harvesting and Tactile Sensing

Abstract

Skin-actuated\nself-powered devices based on triboelectric nanogenerators\n(TENGs) have recently garnered increasing attention, as they can be\nused to develop electronic skins for healthcare, robotic intelligence,\nand human interface devices. TENGs typically require tribonegative\nmaterials to enable the top layers to either be in contact with or\nbe insulated from other specific materials, resulting in suboptimal\nperformance under practical conditions. Here, we describe the fabrication\nof a soft, transparent, flexible, stretchable, and skin-actuated TENG\ndevice using nanostructured polydimethylsiloxane with a silver nanowire\ntransparent contact as a power source to activate commercial small\nelectronic devices. The nanostructured TENG exhibited a high open-circuit\nvoltage of ∼128 V upon contact with the human skin. This value\nwas substantially higher than that of a TENG with no nanostructure\n(∼51.6 V), which was attributed to a higher effective contact\narea in the former. An ∼266 μW/cm² power density\ncould be achieved with the nanostructured TENG upon finger touch stimulation.\nThe resulting electrical output power was then used to activate small\ncommercial electronic devices such as light-emitting diodes. Additionally,\ndue to its high transparency and signal response, the developed TENG\nwas successfully implemented as a sensory platform to build a 3 ×\n3 keypad. The TENG devices were affixed to several objects to monitor\ndaily activities and harvest biomechanical energy. Our findings suggest\nthat the skin-stimulated elastomer-based TENG developed herein could\nopen possibilities in the development of wearable sensors and power\nsources.