Enhanced-performance bio-triboelectric nanogenerator based on starch polymer electrolyte obtained by a cleanroom-free processing method

The study of triboelectric nanogenerators (TENGs) has focused widely on the issue of elevating triboelectrifying capacity. A new recently discovered phenomena of the use of polymers electrolytes for TENGs has been shown to be positive. However, this has not been studied yet in a wide range of materials. Renewable materials, such as biopolymer electrolytes, are still poorly understood regarding their relation to TENG performance. Herein, a polymer electrolyte starch-based bio-TENG was fabricated using a low-cost processing method. The films were electrically characterized at distinct loads, frequencies, thicknesses. Moreover, we complexed the starch polymer with CaCl ₂ to increase the triboelectrifying capacity and performance. Starch films at 0.5% of salt concentration reached the highest voltage output (1.2 V), exceeding by three-fold of the initial output of the non-complexed pristine biopolymer (0.4 V). Furthermore, the electrical output performance varies positively at both thinner film thicknesses and elevated loads while moisture of films has been proved to be a critical parameter in the electrical performance of TENGs, showing that well dried films performed a higher electrical output than moist samples. Furthermore, despite crack generation after fatigue, starch electrolyte films of TENGs showed an inalterable electrical performance suitable for a bunch of applications. To demonstrate one of these applications we achieved to turn on 100 LEDs using starch electrolyte and silicone ecoflex as opponents in a TENG.