Biomimetic metal–organic framework-derived porous carbon welded carbon nanotube networks for strain sensors with high sensitivity and wide sensing range

Abstract

Due to the weak interaction between the adjacent individual fillers of sensing materials, the destruction of conductive percolation network under large and cyclic deformations results in a narrow sensing region and unsatisfactory durability. Inspired by the geometries of spider web and spider slit organ, a versatile strain-sensing platform with metal–organic framework-derived porous carbon-welding carbon nanotube (MPC–w–CNT) percolation networks is reported by soldering the crossing-points of CNTs using MPCs followed by embedding in poly(styrene-block-butadiene-block-styrene) (SBS), which can enable effective transfer of electrons and load among adjacent CNTs as well as avoid the interfacial slippage during cyclic processes of stretching-releasing. The junction bonding could enable the bioinspired strain sensors to detect small and large deformations with a low limit of detection (0.0085% strain), a large sensing region (∼640% strain), high sensitivity (∼7378.26), and short response time (∼122.50 ms), along with excellent reliability (∼1,000 stretching-releasing cycles). The superiority of these sensing performances is assigned to the combination of welding design of hierarchical MPC–w–CNT networks and selection of SBS. These excellent sensing performances allow the bioinspired sensors to detect the full range of human movements. The unique junction bonding strategy can be applied in other nanomaterial systems to develop stretchable electronics.