Embedded carbon nanotube thread piezoresistive strain sensor performance
Abstract
Purpose
Carbon nanotube (CNT) thread ' s piezoresisitive strain sensing properties of gauge factor, linearity, hysteresis, consistency, temperature stability, and bandwidth were evaluated. This evaluation was motivated by little information in literature combined with the need to understand these properties for commercial use. The paper aims to discuss these issues.
Design/methodology/approach
The study here analyzes as-spun CNT thread built into unidirectional glass fiber composites and mounted onto aluminium beams with epoxy to evaluate strain sensing properties. The analyses utilize known sensor parameter definitions to quantify sensor performance.
Findings
CNT thread can provide reliable and robust strain measurements for composite and metallic structures. The strain sensor performance meets or exceeds other strain sensors in performance.
Research limitations/implications
CNT thread ' s piezoresistive effect is not well understood in terms of Poisson ' s ratio and nanotube contact. More research needs to be carried out to better understand this relationship and optimize the sensor thread.
Practical implications
CNT thread can be utilized as a robust strain sensor for composite and metallic structures. It can also be built into composite materials for embedded strain and damage monitoring. By monitoring composite materials with the sensor thread, reliability will significantly increase. In turn, this will lower safety factors and revolutionize inspection methods for composite materials.
Originality/value
This paper is the first to comprehensively evaluate key strain sensing properties of CNT thread. With all this strain sensor information in one spot, this should help expedite the use of this technology in other research and industry.
Keywords
Acknowledgements
The lead author would like to thank the National Science Foundation Graduate Research Fellowship Program for their support. This material is based upon work supported by the National Science Foundation under Grant No. 1102690. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The author would also like to thank Doug Hurd, manager of the machine shop at UC, for his advisement in test rig design and composite material manufacturing. The author would also like to thank Wenyu Zhao, of the University of Cincinnati Center for Intelligence Maintenance Systems (www.imscenter.net/), for his generosity in borrowing a NI 9205 DAQ system long term. Finally, the author would like to thank Dr Allemang and Dr Phillips of the University of Cincinnati Structural Dynamics and Research Lab (SDRL, http://sdrl.uc.edu/) for their generosity for borrowing a shaker, sensors, a FRF analyzer, and lab space to perform the strain bandwidth work. These individuals also provided suggestions in design of the calibration rig, analysis techniques, and general suggestions. Their advisement is greatly appreciated.
Citation
Schulz, M., Song, Y., Hehr, A. and Shanov, V. (2014), "Embedded carbon nanotube thread piezoresistive strain sensor performance", Sensor Review, Vol. 34 No. 2, pp. 209-219. https://doi.org/10.1108/SR-04-2013-653
Publisher
:Emerald Group Publishing Limited
Copyright © 2014, Emerald Group Publishing Limited