ZnO nanorods/carbon black-based flexible strain sensor for detecting human motions

The development of flexible electronics has an important impact on areas ranging from stretchable sensors and bendable batteries to wearable devices. Here, a facile, effective, low-cost, and convenient strategy has been employed to fabricate flexible strain sensor with hexagonal ZnO nanorods (NRs) and carbon black as sensing elements, polydimethylsiloxane (PDMS) as matrix, and latex film as substrate. The as-assembled strain sensors hold the merits of high flexibility, high sensitivity, large workable strain range, good linearity, and ideal stability. Compared to the carbon black-based sensor, the ZnO/carbon black-based sensor exhibits highly enhanced sensitivity under tensile stress. The ZnO/carbon black-based sensor also demonstrates the capability of detecting and differentiating various degrees of human motions such as wrist rotation, knee flexion, and finger tapping, as well as the competence of monitoring human activity like pulse beat. The present method for the assembly of the ZnO-based flexible strain sensor opens up a new route for the fabrication of other wearable flexible electronics. (C) 2017 Elsevier B.V. All rights reserved.