A low-cost 3D flexible pressure sensor with a wide working range prepared from articles for daily use for monitoring human motion

[Display omitted] •A three-dimensional piezoresistive sensor prepared from articles for daily use.•The sensor has a wide working range of 150 kPa.•The sensor can monitor various physiological activities. Flexible piezoresistive pressure sensors have attracted extensive attention due to their portability, flexibility, and high sensitivity. The development of low-cost, high-performance flexible piezoresistive sensors is a key issue. We have prepared a three-dimensional (3D) Carbon@MF flexible piezoresistive pressure sensor by dipping melamine foam (MF) in inexpensive ink with amorphous carbon materials. The material cost per unit volume (cm3) is only $0.006. The sensor has excellent sensing performance: wide working range of 150 kPa, high sensitivity of 0.62 kPa−1, superior stability with 2500 cycles of loading, fast response ability (30 ms). The sensor can monitor various human physiological activities such as different breathing modes, pulse, limb bending, and walking speed etc.