Piezoresistive MXene@CNTs Nanofiber Membrane Sensors with Micro-Hemispherical Structures via Template-Assisted Electrospinning for Human Health Monitoring

With the development of the internet of things (IoT) and the rise of the concept of the internet of everything, wearable sensor devices are booming as mobile terminals and have a huge market value. However, the fabrication of nanofiber membrane-based pressure sensors with special microstructures remains a significant challenge. In this study, template-assisted electrospinning was used to fabricate microhemispherical thermoplastic polyurethane (TT) nanofiber membranes. The preparation of MXene@CNTs/TT (MCTT) nanofiber membranes was conducted via the ultrasound-assisted dip-coating method, utilizing MXene and carbon nanotubes (CNTs) as composite conductive materials. Subsequently, polydimethylsiloxane (PDMS) encapsulation was employed to prepare PDMS-MCTT conductive nanofiber membranes. Utilizing an aligned assembly strategy based on the microhemispherical structure, the PDMS-MCTT bilayer pressure sensor exhibits high sensitivity (Smax = 471.3 kPa–1), wide pressure range (0–521.6 kPa), low detection limit (0.003 kPa), fast response time (7 and 8 ms) and reliable cycling performance (3000 cycles). In addition, the sensor offers excellent breathability and hydrophobicity (contact angle of 132.7°). Usefulness of the sensor in detecting body signals highlights its potential for motion detection and health monitoring.