Highly Sensitive Ultrathin Flexible Thermoplastic Polyurethane/Carbon Black Fibrous Film Strain Sensor with Adjustable Scaffold Networks

HighlightsThe sensors displayed high sensitivity (8962.7), fast response time (60 ms), outstanding stability and durability (>10,000 cycles) and widely workable stretching range (0-160%).A theoretical approach was used to analyze mechanical property, and a model based on tunneling theory was modified to describe the relative change of resistance.Two equations were proposed and offered an effective but simple approach to analyze the change of number of conductive paths and distance of adjacent conductive particles. AbstractIn recently years, high-performance wearable strain sensors have attracted great attention in academic and industrial. Herein, a conductive polymer composite of electrospun thermoplastic polyurethane (TPU) fibrous film matrix-embedded carbon black (CB) particles with adjustable scaffold network was fabricated for high-sensitive strain sensor. This work indicated the influence of stereoscopic scaffold network structure built under various rotating speeds of collection device in electrospinning process on the electrical response of TPU/CB strain sensor. This structure makes the sensor exhibit combined characters of high sensitivity under stretching strain (gauge factor of 8962.7 at 155% strain), fast response time (60 ms), outstanding stability and durability (>10,000 cycles) and a widely workable stretching range (0-160%). This high-performance, wearable, flexible strain sensor has a broad vision of application such as intelligent terminals, electrical skins, voice measurement and human motion monitoring. Moreover, a theoretical approach was used to analyze mechanical property and a model based on tunneling theory was modified to describe the relative change of resistance upon the applied strain. Meanwhile, two equations based from this model were first proposed and offered an effective but simple approach to analyze the change of number of conductive paths and distance of adjacent conductive particles.

Automated summary

This study developed a high-performance wearable strain sensor with high sensitivity, fast response time, outstanding stability and durability, and a wide stretching range. The influence of the stereoscopic scaffold network structure on the electrical response of the sensor was investigated. Theoretical analysis and modeling based on tunneling theory provided insights into the mechanical properties and changes in resistance, with two equations proposed for analyzing the number of conductive paths and distance between conductive particles.