This study presents a novel flexible strain sensor for real-time strain sensing. The material for strain sensing is single-walled carbon nanonets, grown using the alcohol catalytic chemical vapor deposition method, that were encapsulated between two layers of Parylene-C, with a polyimide layer as the sensing surface. All of the micro-fabrication was compatible with the standard IC process. Experimental results indicated that the gauge factor of the proposed strain sensor was larger than 4.5, approximately 2.0 times greater than those of commercial gauges. The results also demonstrated that the gauge factor is small when the growth time of SWCNNs is lengthier, and the gauge factor is large when the line width of the serpentine pattern of SWCNNs is small.
References
[1]
Yang, P.F.; Bruggemann, G.P.; Rittweger, J. What do we currently know from in vivo bone strain measurements in humans? J. Musculoskelet & Neuronal Interact 2011, 11, 8–20.
[2]
Umbrecht, F.; Wagli, P.; Dechand, S.; Gattiker, F.; Neuenschwander, J.; Sennhauser, U.; Hierold, C. Wireless implantable passive strain sensor: Design, fabrication and characterization. J. Micromechanic. Microengineer 2010, doi:10.1088/0960-1317/20/8/085005.
Semet, V.; Binh, V.T.; Guillot, D.; Teo, K.B.K.; Chhowalla, M.; Amaratunga, G.A.J.; Milne, W.I.; Legagneux, P.; Pribat, D. Reversible electromechanical characteristics of individual multiwall carbon nanotubes. Appl. Phys. Lett 2005, 87, 223103.
[7]
Lin, C.M.; Lee, Y.T.; Yeh, S.R.; Fang, W. Flexible carbon nanotubes electrode for neural recording. Biosens. Bioelectron 2009, 24, 2791–2797.
[8]
Lu, J.W.; Wang, W.L.; Liao, K.J.; Wan, B.Y. Strain-induced resistance changes of carbon nanotube films. Int. J. Mod. Phys. B 2005, 19, 627–629.
[9]
Jang, H.S.; Lee, Y.H.; Na, H.J.; Nahm, S.H. Variation in electrical resistance versus strain of an individual multiwalled carbon nanotube. J. Appl. Phys 2008, 104, 114304.
[10]
Park, M.; Kim, H.; Youngblood, J.P. Strain-dependent electrical resistance of multi-walled carbon nanotube/polymer composite films. Nanotechnology 2008, 19, 055705.
[11]
Slobodian, P.; Riha, P.; Lengalova, A.; Olejnik, R.; Kimmer, D.; Saha, P. Effect of compressive strain on electric resistance of multi-wall carbon nanotube networks. J. Exp. Nanosci 2011, 6, 294–304.
[12]
Dharap, P.; Li, Z.L.; Nagarajaiah, S.; Barrera, E.V. Nanotube film based on single-wall carbon nanotubes for strain sensing. Nanotechnology 2004, 15, 379–382.
[13]
Li, X.; Levy, C.; Elaadil, L. Multiwalled carbon nanotube film for strain sensing. Nanotechnology 2008, 19, 045501.
[14]
Yamada, T.; Hayamizu, Y.; Yamamoto, Y.; Yomogida, Y.; Izadi-Najafabadi, A.; Futaba, D.N.; Hata, K. A stretchable carbon nanotube strain sensor for human-motion detection. Nature Nanotechnol 2011, 6, 296–301.
[15]
Chang, N.K.; Su, C.C.; Chang, S.H. Fabrication of single-walled carbon nanotube flexible strain sensors with high sensitivity. Appl. Phys. Lett 2008, 92, 063501.
[16]
Liu, Y.; Chakrabartty, S.; Gkinosatis, D.S.; Mohanty, A.K.; Lajnef, N. Multi-Walled Carbon Nanotubes/Poly(L-lactide) Nanocomposite Strain Sensor for Biomechanical Implants. Proceedings of IEEE Biomedical Circuits and Systems Conference, BIOCAS 2007, Montreal, QC, Canada, 27–30 November 2007; pp. 119–122.
[17]
Stampfer, C.; Jungen, A.; Linderman, R.; Obergfell, D.; Roth, S.; Hierold, C. Nano-electromechanical displacement sensing based on single-walled carbon nanotubes. Nano Lett 2006, 6, 1449–1453.
[18]
Jan, E.; Kotov, N.A. Successful differentiation of mouse neural stem cells on layer-by-layer assembled single-walled carbon nanotube composite. Nano Lett 2007, 7, 1123–1128.
[19]
Giacchino, L.; Tai, Y.C. Parylene-membrane piezoresistive pressure sensors with XeF2-Etched cavity. Proceedings of 2008 IEEE Sensors, Lecce, Italy, 26？29 October 2008; pp. 1568–1571.
[20]
Ziegler, D.; Suzuki, T.; Takeuchi, S. Fabrication of flexible neural probes with built-in microfluidic channels by thermal bonding of parylene. J. Microelectromech. Syst 2006, 15, 1477–1482.
Shiau, S.H.; Liu, C.W.; Gau, C.; Dai, B.T. Growth of a single-wall carbon nanotube film and its patterning as an n-type field effect transistor device using an integrated circuit compatible process. Nanotechnology 2008, 19, 105303.
