A Percolation Model for Piezoresistivity in Conductor–Polymer Composites
Abstract
Insulating polymer composites with conductive filler particles are attractive for sensor applications due to their large piezoresistive response. Composite samples composed of a polymer matrix filled with particles of doped semiconductor that gives a piezoresistive response that is 105 times larger than that of bulk semiconductor sensors are prepared here. The piezoresistance of such composite materials is typically described by using a tunneling mechanism. However, it is found that a percolation description not only fits prior data better but provides a much simpler physical mechanism for the more flexible and soft polymer composite prepared and tested in this study. A simple model for the resistance as a function of applied pressure is derived using percolation theory with a conductivity exponent, s. The model is shown to fit experimental piezoresistive trends with the resistance measured both perpendicular and parallel to the pressure direction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 03, 2018
- Source ID
- 10.1002/adts.201800125
Entities
People
- Adam E. Jakus
- G. Jeffrey Snyder
- Jun Peng
- Kazuki Imasato
- Matthew Grayson
- Mingyi Wang
- Nicholas R. Geisendorfer
- Ramille N. Shah
- Ramya Gurunathan
Organizations
- Defense Advanced Research Projects Agency
- Donghua University
- National Science Foundation
- Northwestern University