Carbon Nanofibrous Aerogels Derived from Electrospun Polyimide for Multifunctional Piezoresistive Sensors

Abstract

The fabrication of carbon aerogels with ultralow density, high electrical conductivity, and ultraelasticity still remains substantial challenges. This study utilizes electrospun polyimide aerogel as the source to fabricate flexible carbon nanofibrous aerogel (PI-CNA) capable of multifunctional applications. The lightweight PI-CNA based piezoresistive sensor shows a wide linear range (0−217 kPa), rapid response/recovery time, and fatigue resistance (12,000 cycles). More importantly, the superior pressure sensing enables the PI-CNA for allrange healthcare sensing, including pulse monitoring, physiological activity detection, speech recognition, and gait recognition. Moreover, the EMI SE and the A coefficient of the PI-CNA reach 45 dB and 0.62, respectively, indicating the outstanding absorption dominated EMI shielding effects due to the multiple reflections and absorption. Furthermore, PI-CNA exhibits satisfying Joule heating performance up to 120 °C with rapid response time (10−30 s) under low supply voltages (1.5−5 V) and possesses sufficient heating reliability and repeatability in long-term repeated heating/cooling cycles. The fabricated PI-CNA shows significant potential applications in wearable technologies, energy conversion, electronic skin, and artificial intelligence.

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

“…Finally, Table 1 presents a comparison of the performance of the PEDOT:PSS@PI sensor in this study and the piezoresistive pressure sensors that were recently reported. 27,42,43,54,61,64–66 Our PEDOT:PSS@PI sensor exhibits fast response times, along with a high gauge factor of up to 4.06, and provides a wide measuring range spanning approximately 0 to 80%, equivalent to roughly 250 kPa. This suggests that the created sensor is suitable for measuring both gentle pressure and significant forces.…”

“…Additionally, PI nanofiber-based pressure sensors have been extensively documented. 9,43–45 For instance, Shaohua et al produced electrospun PI fiber-coated silver nanowire (AgNW) sponges, 44 while Lei et al produced an elastic aerogel made of Ti 3 C 2 T x MXene with 3D “lamella-pillar” microporous structures, achieved by cross-linking and intercalating electrospun polyimide nanofibers (PINFs). 45 These materials exhibited weak fiber interactions, resulting in limited mechanical characteristics (with a maximum strain of 50% and a maximum stress of approximately 3.5 kPa) and a constrained detection range, reaching only a compressive strain of up to 50%, corresponding to 8 kPa of stress, respectively.…”