Silkworm-Shaped MoS2 Growing on Graphene Foam for Highly Sensitive and Flexible Strain Sensor with Full-Scale Human Motion Detection Ability

Abstract

High-performance piezoresistive strain sensors (PSS) are important components of wearable electronics for human health management and are considered a key technology for future applications in fields such as artificial intelligence and human medical monitoring. Recently, many PSS have been developed based on a variety of electrosensitive materials. Among them, 3D graphene foams (GrF) have attracted significant attention owing to their excellent thermal conductivity, tensile properties, and light weight. Herein, a novel GrF-based composite is developed by growing 2D molybdenum disulfide (MoS₂) nanosheets directly. Many lathy nanosheets stand vertically on the GrF, similar to silkworms creeping on the leaf, making the composite more sensitive to mechanical deformation stimuli. The obtained MoS₂@GrF composite is processed into PSS with a wide sensing range (0%–80%), high gauge factor values (16 below 1% and 39 over 40%), detection limit of 0.1% strain with 106/123 ms response/recovery time, and good cyclic stability (≥3000 cycles). Moreover, the as-fabricated strain sensors exhibit excellent Joule heating performance, which can be adjusted by strain. As such, the PSS allows for full-range body motion monitoring and thermal management, which has great potential for next-generation smart wearable electronics.