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论文类型：期刊论文

发表时间：2019-03-01

发表刊物：CARBON

收录刊物：SCIE、Scopus

卷号：143

页面范围：743-751

ISSN号：0008-6223

关键字：Spray-on sensor; Nanocomposite piezoresistive sensor; Broadband ultrasound; Ultrafast response

摘要：We present a nano-engineered thin-film-type piezoresistive sensor, coatable or sprayable on a medium surface for in-situ acquisition of broadband ultrasound up to 1.4 MHz - a trait of nanocomposite-based piezoresistive sensing devices that has until now not been discovered and explored. With polyvinylidene fluoride as the matrix, fabrication of the spray-on sensor is attempted in a comparative manner, with multiscale nanofillers ranging from zero-dimensional carbon black, through one-dimensional multiwalled carbon nanotubes, to two-dimensional graphene nanoparticles. With a morphologically optimal nano-architecture, the quantum tunneling effect can be triggered in the percolating nanofiller network when ultrasound signals traverse the sensor, inducing dynamic alteration in the piezoresistivity manifested by the sensor. In-situ morphological analysis and experiment reveal high fidelity, ultrafast responses, and high sensitivity of the sensor to dynamic disturbance, from static strain to ultrasound in a regime of megahertz yet with an ultralow magnitude (of the order of microstrain or nanostrain). These findings are remarkable as no other investigation has probed the response of nanocomposite piezoresistive sensors over such a broad frequency spectrum. (C) 2018 Elsevier Ltd. All rights reserved.