High-Performance Polyimide Aerogel Film-Based Triboelectric Nanogenerator for Trace Liquid Analyzing

Aerogelsexhibit excellent sensing performance thanks to theirhigh porosity, large specific surface area, and remarkable mechanicalproperty. However, the prevalent aerogel-based analyzers fail to detectliquid in a way of low detection limit, fast response, and good robustness.Here, we have fabricated a polyimide aerogel (PIA) film with porosityup to 98.01% and thickness about 220 mu m and built a liquid analyzerwith this PIA film as a tribo-negative layer. The liquid analyzercan respond to different liquid droplets on the basis of liquid-solidinteraction and the triboelectric effect. Benefitting from the mesoporousstructure, high porosity, low thickness, and stable compression performanceof the PIA film, the liquid analyzer shows fast response and goodrobustness for detecting different liquids down to 7 mu L. Themechanisms of the analyzer for distinguishing liquids are discussedfrom the aspects of effective relative permittivity, the interactionbetween liquid and PIA film, and transfer charge quantity. The traceliquid analyzers based on high-performance PIA films provide supportfor the development of environmental protection and biochemical sensingand show huge application potential in sensing related areas.