Self-Powered Acetone Sensing under High Humidity Enabled by a No-Contact Single-Electrode Triboelectric Nanogenerator

In this study, a single-electrode triboelectric nanogenerator (TENG) based on chitosan/SnO 2 composite films for self-powered acetone sensing was reported, with particular attention paid to operation under highly humid conditions. The TENG works through periodic contact and separation between a PTFE film and a nylon-encapsulated structure. By introducing SnO 2 nanoparticles into the chitosan matrix, the sensing behavior is markedly enhanced. Among the different films investigated, the spray-coated bilayer chitosan/SnO 2 film exhibited the best overall performance. Specifically, it delivered a response of 48.7% to 10 ppm acetone at 97.3% relative humidity (RH), which is substantially higher than that of the pure chitosan film (5.1%) and the blended composite film (24.6%). In addition, the s -Chitosan/SnO 2 -based device showed excellent resistance to humidity interference: its response at 97.3% RH was only 1.2 times higher than that measured at 32.8% RH, outperforming the pure chitosan film, which showed a 2.4-fold increase. The sensing mechanism is attributed to the interaction between acetone molecules and the hydrogen-bond network formed among chitosan, water molecules, and SnO 2 . Acetone disrupts these hydrogen bonds, leading to changes in surface charge density and, consequently, in the electrical output of the TENG. Overall, this work provides a feasible strategy for developing room-temperature, self-powered acetone sensors with strong humidity tolerance, making them attractive for noninvasive health monitoring applications such as diabetes screening.