Triboelectric Nanogenerators (TENGs) Based on Various Flexible Polymeric Materials Along With Printed and Non-Printed Electrodes

Four designs (D1–D4) of flexible triboelectric nanogenerators (TENGs) were successfully fabricated in three different configurations for energy harvesting applications. Typically, TENG consists of anode layer, cathode layer, and electrodes. Combination of materials were investigated in this study using polyethylene terephthalate (PET), thermoplastic polyurethane (TPU) and a flexible fabric as top triboelectric (cathode) layers; Kapton and polydimethylsiloxane (PDMS) as bottom triboelectric (anode) layers. Copper (Cu) tape and screen-printed silver (Ag) were used as electrodes. Each of these designs (D1–D4) has three configurations C1–C3 in which the top substrate (cathode layer) was different from one configuration to other. In order to determine the best material combination that would provide better TENG performance, different configurations were considered. The capability of the TENGs in terms of open circuit voltage ( $V_{\mathrm {oc}}$ ) and short circuit current ( $I_{\mathrm {sc}}$ ) were demonstrated by subjecting them to $\sim 5$ –6 N force at 10 Hz operating frequency. A maximum $V_{\mathrm {oc}}$ of 21.61 ± 2.27, 35.32 ± 0.89, 31.21 ± 1.43, and 45.75 ± $5.09~V_{\mathrm {pp}}$ resulted in a power density of 0.29, 1.12, 0.47, and $0.91~\mu \text{W}$ /cm ² from the D1–D4 designs, respectively. The TENG fabricated using screen printed Ag flake on PDMS and fabric (D4) exhibited the highest open circuit output and a good repeatability after six months of re-testing with a maximum difference of ~7.39% change ( $\Delta V /V)$ in the output signal. In addition, a cyclic test was performed on D4, the results obtained demonstrate a good durability of the TENG sensor over 1000 cycles. The fabricated TENG device has a simple design, compact size, and demonstrated a better performance in comparison with some of the other works in terms of output voltage.