Exploring charge regeneration effect in interdigitated array electrodes-based TENGs for a more than 100-fold enhanced power density

The vast potential of harnessing high entropy and abundantly available mechanical energy through triboelectric nanogenerators (TENGs) has attracted significant attention in recent years. However, the cost of harvesting this energy has often outweighed the energy collected. Recent advancements in TENGs for blue energy harvesting from water flow have shown great promise. In this study, we present a novel approach to optimize the performance of interdigitated electrode array-based TENGs operating in free-standing mode (IDA-FTENG) by introducing a gap-to-width ratio (GWR) relationship for the electrodes and its impact on the charge regeneration effects. We investigate the dependence of the charge regeneration effect on GWRs and the number of electrode pairs to enhance the performance of IDA-FTENGs, employing a rapid and industrially scalable laser scribing process for fabricating the devices. An optimized device, featuring a maximum of 34 interdigitated electrode grids, demonstrates a 140-fold increase in power density compared to conventional single electrode pair TENGs (SEP-TENGs). Furthermore, power density projections indicate that the optimized IDA-FTENGs can compete with current solar cells, if designed suitably. We showcase the applicability of the proposed IDA-FTENG devices in self-powered sensors, autonomous wireless operations, security monitoring, and smart home systems. This research explores the effect of charge regeneration and provides a unique approach to designing and optimizing highly efficient mechanical energy harvesters (IDA-FTENG). With optimized device configurations, using a 34-finger array of electrode pairs, we generate 140 times more power density compared to the conventional TENG to amplify the power output. These results demonstrate the utility of the IDA-FTENG in self-powered sensors at the human-machine interface, security monitoring, and smart home systems for future IoT. • As never before, a unique gap-to-width (GWR) relationship was derived to explore the charge regeneration effect in IDA-FTENG. • A record 34 ITO electrode pairs on a PET sheet (6×4.7 cm 2 ) shows a pathway for developing flexible pressure sensors. • IDA-FTENG with high electrode pair density showed 140 times increased power density due to the high charge regeneration effect. • Hypothetical available power of the state-of-the-art works highlights the scope for the improvement in TENGs performance. • The estimated power density of IDAF-TENG with 204 electrodes pair can be compared to the efficiency of the solar cells.