Enhanced On-Demand Antibacterial Platform Based on Triboelectric-Nanogenerator-Induced Electrical Stimulation of Cu2S 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 Cu2S substrates, benchmarked against Cu2O. Submicron-structured Cu2S layers were fabricated via a novel sulfurization method applied to electrodeposited Cu2O layers on fluorine-doped tin oxide (FTO) substrates. The resulting Cu2S and Cu2O 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 Cu2S, increasing its efficacy against bacterial models of Staphylococcus aureus and Escherichia coli from 25% to 70% and from 55% to 100%, respectively. In contrast, Cu2O demonstrated high intrinsic antibacterial activity with minimal improvement under TENG stimulation. The enhanced response of Cu2S was attributed to a ∼115% increase in Cu ion release, significantly higher than the ∼17% increase observed for Cu2O. 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.