Highly Stretchable Strain Sensor with Both an Ultrawide Workable Range and an Ultralow Detection Limit for Human Health Monitoring

Abstract

Ultrahigh performance and versatile flexible piezoresistive strain sensors have received tremendous attention in scientific and commercial societies, yet the trade-off between hypersensitivity and the broad detection range of strain sensors still hinders their practical applications. Herein, we combined an electrospinning technique with an ultrasonication anchoring technique to easily fabricate a highly elastic and conductive electrospun carbon black (CB)/olefin block copolymers (OBCs)/polyethylene glycol (PEG) fibrous film for an ultrahigh performance piezoresistive strain sensor. This article demonstrates the influence of different contents of PEG in the electrospinning process on the mechanical properties of elastic substrate OBCs/PEG. Benefiting from the high mechanical strength, low hysteresis, and appropriate modulus of OBCs/PEG, as-developed conductive microfibers can be applied as a strain sensor, which exhibits a high gauge factor of up to 1903, a fast response/recovery time (87 ms/96 ms), outstanding stability and durability (>10,000 cycles at a strain of 150%), and an ultrabroad detection range (0.15–750%). Moreover, the CB/OBCs/PEG (COP) fabric can be applied to bioelectrodes to record electrocardiograms (ECGs). This ultrahigh performance piezoresistive strain sensor has promising applications in human–machine interactivity, flexible tactile electronic skin, and personal health monitoring systems.