Enhanced On-Demand Antibacterial Platform Based on Triboelectric-Nanogenerator-Induced Electrical Stimulation of CuS Substrates.

Triboelectric nanogenerators (TENGs) offer a sustainable, battery-free solution for wearable electronics by converting motion into energy. However, direct skin contact poses bacterial contamination risks, requiring advanced antibacterial strategies. This study developed an on-demand antibacterial platform based on TENG-induced electrical stimulation of CuS substrates, benchmarked against CuO. Submicron-structured CuS layers were fabricated via a novel sulfurization method applied to electrodeposited CuO layers on fluorine-doped tin oxide (FTO) substrates. The resulting CuS and CuO thin films were integrated into a single-electrode TENG system, and their antibacterial efficacy was evaluated under electrical stimulation driven by a Kapton-FTO TENG.Experimental results revealed that a 10-min finger-tapping-generated electrical current from the TENG significantly enhanced the antibacterial performance of CuS, increasing its efficacy against bacterial models of and from 25% to 70% and from 55% to 100%, respectively. In contrast, CuO demonstrated high intrinsic antibacterial activity with minimal improvement under TENG stimulation. The enhanced response of CuS was attributed to a ∼115% increase in Cu ion release, significantly higher than the ∼17% increase observed for CuO. This enhanced performance was further attributed to intensified electrostatic interactions between positively charged electrode surfaces and negatively charged bacterial membranes, leading to membrane interruption and bacterial death. Additionally, electron capture from bacterial electron transport chains heightened oxidative stress, disrupted energy metabolism, and further enhanced antibacterial effects. These findings accentuate the potential for integrating TENGs into biomedical applications, particularly in advanced wearable devices, to provide inherent antibacterial functionality for safe and effective direct human contact.