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 <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> 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.