Ultra-highly sensitive, low hysteretic and flexible pressure sensor based on porous MWCNTs/Ecoflex elastomer composites

In this paper, a new method was proposed to improve the sensitivity of capacitive-type pressure sensors by using the high dielectric constant materials as dielectric layer of sensors. The porous multi-wall carbon nanotubes (MWCNTs)/Ecoflex elastomer composites with high dielectric constant were prepared to serve as dielectric layers of capacitive-type pressure sensors. The MWCNTs/Ecoflex elastomer composite sensors show ultra-high sensitivity of 2.306 kPa−1, wide dynamic range and low hysteresis. The as-prepared sensors can monitor the response to pressure below 2.6 Pa. Moreover, they have exhibited excellent performances in promising practical applications as wearable devices in detecting pulses of carotid artery and heartbeats. This strategy proposed here presents a promising way to obtain high performance pressure sensors for applications in E-skin, robotics, wearable medical aids and real-time tactile sensing systems.