3D printed flexible triboelectric nanogenerator with viscoelastic inks for mechanical energy harvesting

Abstract

With the rising development of the portable and wearable sensors and displays, the compact power source devices have become increasingly important and indispensable in our daily life. In this study, a flexible triboelectric nanogenerator (TENG), fabricated by the direct ink writing (DIW) method, has been proposed for the purpose of vibration energy harvesting to support power for these electronic devices. To strengthen the effective contact area of the opposite triboelectric polarities, the silicone elastomer, as viscoelastic inks, is extruded out directly onto the aluminum foil through the nozzle tip to construct the triboelectric patterns with rich and regular micro structures on the surface. Various film thickness, printing fibers spaces, contact frequencies, applied forces and printing paths are investigated to better understand the effects of the printing parameters in detail. The results show that the TENG can yield an output voltage of 124 V and the corresponding maximum power density of 608.5 mW/m2. Meanwhile, via vibration energy harvesting, the TENG is demonstrated to sustainably drive 51 LEDs and a 3-in. electrowetting display. Our work paves a new way for the individual design and digital manufacture of friction surface structures for the flexible, stretchable and wearable TENG.