Microstructured carbon black/CNT/epoxy nanocomposite sensor with high sensitivity yet wide detection range

In recent years, flexible pressure sensors with wide detection ranges have gained extensive attention. However, maintaining a high sensitivity yet a wide effective pressure-detection range through simple microstructure-regulation strategies remains a great challenge. Herein, a microstructured carbon black/carbon nanotube (CNT)/epoxy nanocomposite (MCC) sensor was prepared using a simple two-step replication strategy via the non-orthogonal micro-wall arrays of stainless-steel cloth. Due to the decreased compressive modulus by introducing micro-wall arrays and the temperature-adjustable compressive modulus of the epoxy used, the MCC obtained exhibits a wide modulation range of compressive modulus from 7.0 kPa to 29.9 ​kPa at the strain of 0% to 10%, and 0.86 MPa to 1.1 MPa at the strain of 10% to 30% by adjusting temperature. Consequently, the as-prepared MCC-based pressure sensor shows a high sensitivity of 23.8 kPa −1 in the pressure range of 0 kPa to 30 kPa, and a wide linear response range of 0 kPa to120 kPa and an effective detection range of 0.015 kPa to 320 kPa in the frequency range of 0 Hz to 5 Hz, which are much wider than those of most flexible pressure sensors reported. Due to its wide detection range, fast response and excellent reliability, the MCC sensor is capable of monitoring human motions of various pressure-levels, including arterial pulse, finger, hand and leg movements, thus showing a great potential in wide application scenarios.