Transparent and flexible touch on/off switch based on BaTiO3/silicone polymer triboelectric nanogenerator

Tactile sensors and wearable electronics based on triboelectric nanogenerators (TENGs), which convert environmental mechanical energy to the electrical energy, have extensive applications. Features such as flexibility, low weight, biocompatibility and transparency make energy generators, more eminent and practical. In this study, an elastic and non-opaque silicone-based polymer has been utilized as a charge generating layer of the TENGs. In order to improve the triboelectric properties as well as enhancement of the induced electrical charge, it was composited with various materials including TiO2, BaTiO3, Al2O3, ZnO, CaCO3 and graphene oxide. The flexible TENG’s maximum output power density of 10.10 W/m2, voltage of 660 V and current of 72 μA was obtained from the Si polymer/BaTiO3 composite layer with the fracture stain of 260% on the aluminum contact (94% and 92% enhancement compared to the pure Si polymer, in voltage and current respectively). For the purpose of making a transparent, elastic and ultra-lightweight TENG, composite layer were deposited on a conductive electrode based on silver nanowires (AgNWs). The built-in nanogenerator had the transparency of 79%, output power density of 27 kW/m3 and weight of 8 mg/cm2. It has been employed as a transparent, elastic, flexible and ultra-lightweight touch on/off switch which is applicable in harsh environmental conditions and utilized as a flexible wristband to switch on/off the LED, thermometer and oximeter device. The introduced large-scale flexible and transparent TENG has a great potential to be applied in smart home applications and wearable electronics.