| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Thin Films | Monday Sessions |
| Session TF-MoE |
| Session: | Electronics and Displays on Flexible and Hard Substrates |
| Presenter: | Takanari Saito, Tokyo University of Agriculture & Technology, Japan |
| Authors: | T. Saito, Tokyo University of Agriculture & Technology, Japan M. Matayoshi, Tokyo University of Agriculture & Technology, Japan J. Shirakashi, Tokyo University of Agriculture & Technology, Japan |
| Correspondent: | Click to Email |
Among the flexible electronic devices, the strain sensors have attracted a great deal of interest due to its wide range of utility in real life, for example, the detection of human motion, monitoring personal health and therapeutics. Previously, we have reported that thin graphite wires are simply and easily fabricated from pyrolytic graphite sheet (PGS) [1] which is commercially available from Panasonic Corporation and have potential applications in microheaters [2]. In this report, we focus on the thin graphite wires fabricated on sticky tapes as flexible devices and investigate the electrical properties of the thin graphite wires for strain sensors.
The experimental procedures are as follows. First, graphite wires with the length of 45 mm and the width of 1 mm were cut off from PGS. Then, we prepared thin graphite wires with thickness down to about 3 μm using mechanical exfoliation. The electrical properties of the thin graphite wires were studied by applying a tensile bending stress with the radius of curvature from 5 to 25 mm. When applying tensile strains by bending the graphite wires, resistance of the graphite wires could show increasing response. The relative change in resistance (ΔR/R0) under a bending radius of 5 mm was 48 %, where R0 is the resistance under zero strain; R is the resistnace under strain; and ΔR=R-R0. It has been proposed that resistance of graphite-based strain sensors under the bending stress changes due to variations in length and cross-sectional area as well as the distance between conductive particles [3]. Hence, the resistance changes of our thin graphite wires are caused by similar mechanism. Therefore, it is suggested that thin graphite wires simply and easily fabricated from PGS can be used as strain sensors.
References
[1] Panasonic Global Industrial Devices Materials - PGS Graphite Sheet
https://industrial.panasonic.com/www-ctlg/ctlg/qAYA0000_WW.html, (Cited 2014)
[2] M. Matayoshi et al., ICN+T (2014 International Conference on Nanoscience + Technology), July 20-25, 2014, Vail,
Colorado, USA.
[3] A. Bessonov et al., Sensors Actuators A: Phys. 206 (2014) 75.