Abstract
Energy harvesting from ambient environmental resources has gained a great attention to power various portable electronics. Among the available renewable resources, it is worth mentioning devices harvesting solar, biochemical, thermal, and mechanical energy. Especially, mechanical energy is abundantly available in our daily life and can be significantly harvested through piezo- and tribo-electric energy harvesters. Triboelectric nanogenerators (TENG) harvesting mechanical energy from human body movements are especially attractive due to its easy adaptation and availability of vast variety of materials. Contact electrification and electrostatic induction are the basic principles behind the energy generation in TENG. Several studies have been done to enhance the output performance of TENG by surface and structural alterations. In this work, a flexible sandwich-type TENG (FS-TENG) based on ridged and biocompatible silicone elastomers and thermoplastic polyurethane has been proposed. The device consists of two nanogenerators stacked together. The interlocking ridged structure and dual nanogenerator architecture provide increased surface area and hence enhanced output. The proposed FS-TENG exhibit open-circuit voltages and maximum power density of ~80 volts and 0.35 mW/cm2, respectively. This preliminary performance already makes the device extremely promising to power low energy smart wearable devices, as well as to monitor pressure in bespoke biomedical applications.