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Mechanoionic Transduction of Solid Polymer Electrolytes and PotentialApplications

Published online by Cambridge University Press:  26 January 2016

Yuta Dobashi
Affiliation:
Advanced Materials and Process Engineering Laboratory, Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4
Graham Allegretto
Affiliation:
Advanced Materials and Process Engineering Laboratory, Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4
Mirza S. Sarwar
Affiliation:
Advanced Materials and Process Engineering Laboratory, Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4
Edmond Cretu
Affiliation:
Advanced Materials and Process Engineering Laboratory, Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4
John D.W. Madden*
Affiliation:
Advanced Materials and Process Engineering Laboratory, Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4
*
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Abstract

A novel pressure sensor is proposed exhibiting generative properties fromdisplacement-induced ionic charge separation in gel electrolytes. Amechano-ionic or ‘piezo-ionic’ effect, in analogy to thewell-known piezoelectric effect, is hypothesized to originate from a differencein mobilities between cationic and anionic species causing a localized ioniccharge gradient upon application of pressure. This gradient can be detected as avoltage or current by using copper electrodes placed at the sides or at regularintervals along a surface of the gel. The voltage generated may be a result ofthe local concentration gradient induced by the deformation of the gel orperhaps is the result of some ions moving faster through the porous gel thanothers. In this work, ionic polymer gels based on Poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) co-polymer were synthesized insitu to incorporate an organic electrolyte consisting ofbis(trifluoromethane)sulfonimide lithium salt in propylene carbonate. With twoelectrodes placed under the gel, the samples were subjected to a sinusoidalmechanical force while open circuit voltage was measured to determine therelationship between electrical signal and mechanical input. The voltagesgenerated are 10’s of mV in magnitude at 1 kPa. Results suggest amaximum sensitivity of 25 µV/Pa at 10 mHz, comparable to the voltagesexpected in piezoelectric polymers such as PVDF (44 µV/Pa for similardimensions). The non-aqueous, solid-state ionic gels presented in this workprovide improved stability and is less prone to evaporation than its aqueous,hydrogel based counterpart. The new mechanism of sensing provides an alternativeto the more rigid and less stretchable piezoelectric sensors.

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Articles
Copyright
Copyright © Materials Research Society 2016 

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References

REFERENCES

Menguc, Y., Park, Y.-L., Pei, H., Vogt, D., Aubin, P. M., Winchell, E., Fluke, L., Stirling, L., Wood, R. J., and Walsh, C. J., “Wearable soft sensing suit for human gait measurement,” Int. J. Rob. Res., vol. 33, no. 14, pp. 17481764, Nov. 2014.CrossRefGoogle Scholar
Berselli, G., Piccinini, M., Palli, G., and Vassura, G., “Engineering Design of Fluid-Filled Soft Covers for Robotic Contact Interfaces: Guidelines, Nonlinear Modeling, and Experimental Validation,” IEEE Trans. Robot., vol. 27, no. 3, pp. 436449, Jun. 2011.CrossRefGoogle Scholar
Tiezzi, P. and Kao, I., “Modeling of Viscoelastic Contacts and Evolution of Limit Surface for Robotic Contact Interface,” IEEE Trans. Robot., vol. 23, no. 2, pp. 206217, 2007.CrossRefGoogle Scholar
Sun, J.-Y., Keplinger, C., Whitesides, G. M., and Suo, Z., “Ionic skin,” Adv. Mater., 2014.CrossRefGoogle ScholarPubMed
us Sarwar, M. S., Dobashi, Y., Scabeni Glitz, E. F., Farajollahi, M., Mirabbasi, S., Naficy, S., Spinks, G. M., and Madden, J. D. W., “Transparent and conformal ‘piezoionic’ touch sensor,” in SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2015, p. 943026.Google Scholar
de Gennes, P. G., Okumura, K., Shahinpoor, M., and Kim, K. J., “Mechanoelectric effects in ionic gels,” Europhys. Lett., vol. 50, no. 4, pp. 513518, May 2000.CrossRefGoogle Scholar
Wu, L., Huang, G., Hu, N., Fu, S., Qiu, J., Wang, Z., Ying, J., Chen, Z., Li, W., and Tang, S., “Improvement of the piezoelectric properties of PVDF-HFP using AgNWs,” RSC Adv., vol. 4, no. 68, p. 35896, Aug. 2014.CrossRefGoogle Scholar
Amsden, B., “Solute Diffusion within Hydrogels. Mechanisms and Models,” Macromolecules, vol. 31, no. 23, pp. 83828395, 1998.CrossRefGoogle Scholar
Fiumefreddo, A. and Utz, M., “Bulk Streaming Potential in Poly(acrylic acid)/Poly(acrylamide) Hydrogels,” Macromolecules, vol. 43, 13, pp. 58145819, 2010.CrossRefGoogle Scholar
Frank, E. H. and Grodzinsky, A. J., “Cartilage electromechanics—II. A continuum model of cartilage electrokinetics and correlation with experiments,” J. Biomech., vol. 20, no. 6, pp. 629639, Jan. 1987.CrossRefGoogle Scholar
Gu, W. Y., Lai, W. M., and Mow, V. C., “Transport of fluid and ions through a porous-permeable charged-hydrated tissue, and streaming potential data on normal bovine articular cartilage,” J. Biomech., vol. 26, no. 6, pp. 709723, Jun. 1993.CrossRefGoogle Scholar