Multi-scale simulations on piezoresistivity of carbon nanofiller/polymer nanocomposites and fabrication of ultrasensitive piezoresistive nanocomposite strain sensors
讲座名称：
Multi-scale simulations on piezoresistivity of carbon nanofiller/polymer nanocomposites and fabrication of ultrasensitive piezoresistive nanocomposite strain sensors
讲座时间：
2015-11-06
讲座人：
胡宁
形式：
校区：
兴庆校区
实践学分：
讲座内容：
应机械结构强度与振动国家重点实验室邀请，重庆大学航空航天学院胡宁教授来我院做学术报告。
报告题目：Multi-scale simulations on piezoresistivity of carbon nanofiller/polymer nanocomposites and fabrication of ultrasensitive piezoresistive nanocomposite strain sensors
报告时间：11月6号（周五）下午4:00
报告地点：学院第二会议室
报告人：胡宁
报告摘要：
In this work, firstly, based on effective multi-scale numerical modeling and simulations, three possible mechanisms of piezoresistivity in polymer nanocomposites with carbon nanofiller (CNF, e.g., carbon nanotube and carbon nanofiber), i.e., 1) variation of conductive networks formed by CNFs; 2) tunneling resistance change in neighboring CNFs and 3) piezoresistivity of CNFs themselves, have been systematically explored. Based on the numerically obtained knowledge for the working mechanisms of the piezoresistivity, a set of resistance-type strain sensors has been fabricated from metal-coated CNF/epoxy nanocomposites. Two nanofillers, i.e., multi-walled carbon nanotubes (MWCNTs) and vapor growth carbon nanofibers (VGCFs) with nickel, copper and silver coatings were used. The ultrahigh strain sensitivity was observed in these novel sensors as compared to the sensors made from the CNFs without metal-coating, and conventional strain gauges. In terms of gauge factor, the sensor made of VGCFs with silver coating is estimated to be 155, which is around 80 times higher than that in a metal-foil strain gauge. In experiments, the possible mechanism responsible for the high sensitivity and its dependence with the networks of the CNFs with and without metal-coating and the geometries of the CNFs were further investigated thoroughly.
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