Lightweight, flexible, and conductive PEDOT:PSS coated polyimide nanofibrous aerogels for piezoresistive pressure sensor application

Abstract

Developing flexible conductive aerogels solely from polymers for pressure sensors frequently faces challenges due to balancing durable mechanical characteristics with responsive conductivity. Here, we introduce an economical and scalable approach to manufacture a compressible and flexible conductive aerogel designed for application in piezoresistive pressure sensors. In a dip-coating process, the conductive aerogel poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)@polyimide (PI) is produced by immersing the polyimide nanofibrous aerogel (PiNFA) in an aqueous dispersion of PEDOT:PSS. SEM, TEM, FTIR, and XPS analyses confirm the existence of a PEDOT:PSS coating on PiNFA without changing the cellular hierarchical microporous structure. PiNFA's porous interconnected structure enables the electrical PEDOT:PSS@PI to exhibit notable compressibility and retain a stable piezoresistive response even up to 80% of compressive strain with a maximum compressive stress of 250 kPa and a relative resistance variation of 96.10%, respectively. The sensitivity of the PEDOT:PSS@PI aerogel, represented by the gauge factor (GF), varies from 4.06 to 0.82 across the 0–80% compression strain range, showcasing its promising versatility for various pressure sensor applications.