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

Abstract

Aerogels\nexhibit excellent sensing performance thanks to their\nhigh porosity, large specific surface area, and remarkable mechanical\nproperty. However, the prevalent aerogel-based analyzers fail to detect\nliquid in a way of low detection limit, fast response, and good robustness.\nHere, we have fabricated a polyimide aerogel (PIA) film with porosity\nup to 98.01% and thickness about 220 μm and built a liquid analyzer\nwith this PIA film as a tribo-negative layer. The liquid analyzer\ncan respond to different liquid droplets on the basis of liquid–solid\ninteraction and the triboelectric effect. Benefitting from the mesoporous\nstructure, high porosity, low thickness, and stable compression performance\nof the PIA film, the liquid analyzer shows fast response and good\nrobustness for detecting different liquids down to 7 μL. The\nmechanisms of the analyzer for distinguishing liquids are discussed\nfrom the aspects of effective relative permittivity, the interaction\nbetween liquid and PIA film, and transfer charge quantity. The trace\nliquid analyzers based on high-performance PIA films provide support\nfor the development of environmental protection and biochemical sensing\nand show huge application potential in sensing related areas.