Tunable stretchable strain sensors enabled by patterned Ecoflex-vertical aligned carbon nanotube arrays and pre-stretching transfer

Abstract

Stretchable strain sensors have drawn tremendous attention due to their wide applications in various emerging scenarios. Various application scenarios have different performance requirements for the sensors, mainly including sensitivity and sensing range. It is necessary but challenging to customize the design to achieve the various required performance. Here, we propose a method to easily modulate stretchable strain sensors by patterning the hybrid film, which infiltrates Ecoflex into the patterned vertical aligned carbon nanotube (VACNT) arrays and combining the pre-stretching transfer. The pre-stretching level of the Ecoflex substrate, the pattern design, and the height of the VACNT arrays are the main factors to modulate the sensitivity and sensing range of the sensors. The typical sensors show tunable sensitivity (from 0.6 to 417.7) and sensing range (from 0-40% to 0–150%), high mechanical repeatability, as well as durability (>10000 operation cycles). The sensors are applied to detect human body motion and recognize speech and emotional signals. These show the application potentials of the sensors in movement monitoring, human-machine interfaces, and electronic skins.