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

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