Highly accurate fabric piezoresistive sensor with anti-interference from both high humidity and sweat based on hydrophobic non-fluoride titanium dioxide nanoparticles

Abstract

Fabric-based piezoresistive sensors have demonstrated great potential in human motion and health detection applications. However, the conductive polymers of sensing units are easily influenced by high humidity and sweat conditions, which result in real-time electrical resistance fluctuation, and ultimately sensing inaccuracy. Herein, a hydrophobic, non-fluoride, titanium dioxide nanoparticle (TiO₂-ODI)-modified fabric-based piezoresistive sensor was firstly employed to obtain accurate pressure sensing by prohibiting the interference from both high humidity and droplets in daily life. Due to the prominent isolation effect of the dense TiO₂-ODI nanoparticle layer, for the first time, the dynamic normalized electrical resistance changes in a fabric-based piezoresistive sensor were negligibly influenced by high humidity of 95% and droplets of water, saline, milk, and sweat. Compared with the original pressure sensor (S = 0.85 kPa⁻¹), the introduction of TiO₂-ODI almost did not sacrifice the sensing performance (S = 0.83 kPa⁻¹) and displayed prominent resistance to sweat interference. Thus, the hydrophobic TiO₂-ODI pressure sensor exhibits promising potential and wide applicability for preparing highly accurate fabric structural piezoresistive sensors with wearing comfort, large area, self-cleaning property, ultraviolet protection, and anti-interference of high humidity and sweaty conditions, such as accurately evaluating human motion during exercise or on a rainy day.