Electro-Mechanical Properties of Knitted Fabric Made From Conductive Multi-Filament Yarn Under Unidirectional Extension

Abstract

A theoretical model for electro-mechanical properties of intrinsically conductive knitted fabrics made from stainless steel multi-filament yarns under large uniaxial deformation is presented. The investigations are focused on the relationship between the load and electrical resistance of the fabric under uniaxial extension. A circuit network is proposed based on the loops configuration and fabric structure. The equivalent resistance of the fabric is obtained by solving the circuit equations of the network. In order to simplify the calculation of the contacting forces on the overlapped yarns, a two-dimensional hexagon model is used to represent the loop configurations. An image-capturing system is employed to record the images of the loop configurations during the extension process and the relationship between the configurations of the loops and the load imposed on the fabric is obtained. From the theoretical analysis and experimental investigations, it is found that the contacting resistance of the overlapped yarns in the fabric is the key factor that governs the sensitivity of the fabric sensor. In addition, the fabric structure that determines the structure of the circuit network is also an important factor affecting the characteristics of the fabric sensor.

Get full access to this article

View all access options for this article.

References

Collins, G. E. , and Buckley, L. J. , Conductive Polymer-Coated Fabrics For Chemical Sensing , Synth. Metals 78 93–101 (1996).

De Rossi, D. , Carpi, F. , Lorussi, F. , Tognetti, A. , Scilingo, E. P. , and Mazzoldi, A. , Electroactive Fabrics for Distributed, Conformable and Interactive Systems . in “Proc. of IEEE Sensors 2002, IEEE International Conference on Sensors,” pp. 1608–1613 , 2002.

De Rossi, D. , Santa, A. and Mazzoldi, A. , Dressware: Wearable Hardware , Mater. Sci. Engng C 7 pp. 31–35 , 1999.

De Rossi, D. , Santa, A. , and Mazzoldi, A. , Dressware: Wearable Piezo-and Thermoresistive Fabrics for Ergonomics and Rehabiliation , in “XIX International Conference of IEEE & EMBS,” Chicago, p. 30-30 1997.

Gregory, R. V. , Kimbrell, W. C. , and Kuhn, H. H. , Conductive Textiles , Synth. Metals, 28(1–2), 823–835 (1989).

Hepworth, B. , and Leaf, G. A. V. , Shape of the Loops in an Undeformed Plain Weft Knit Fabric, Studies in Modern Fabrics: A Report on the 1970 Diamond Jubilee Conference of the Textile Institute, Part 2, 1970 , Text. Inst. Ind. 8, 209–213 (1970).

Holm, R. , “Electric Contacts (Fourth Edition),” Springer-Verlag, Berlin, New York , pp. 7–19 (1967).

Kincal, D. , Kumar, A. , Child, A. D. , and Reynolds, J. R. , Conductivity Switching in Polypyrrole-Coated Textile Fabrics As Gas Sensors , Synth. Metals 92(1), 53–56 (1998).

Kuhn, H. H. , Kimbrell, W. C. , Worrell, G. , and Chen, C. S. , Properties of Polypyrrole Treated Textile for Advanced Applications , Proceedings of the Society of Plastics Engineers’ 49th Annual Technical Conference (ANTEC), Montreal, p. 760–764 (1991).

10.

Leung, M. Y. , Tao, X. M. , Yuen, M. C. W. , and Kwok. W. Y. , Strain Sensitivity of Polypyrrole-coated woven fabrics under unidirectional deformation. Submitted to Text. Res. J., (2004).

11.

Munden, D. L. , The Geometry and Dimensional Property of Plain-Knit Fabrics , J. Text. Inst. 50, 448–471 (1959).

12.

Oh, K. W. , Park, H. J. , and Kim, S. H. , Stretchable Conductive Fabric for Electrotherapy , J. Appl. Polymer Sci. 88, 1225–1229 (2003).

13.

Postle, R. , and Munden, D. L. , Analysis of the Dry-Relaxed Knitted Loop Configuration , J. Text. Inst. 58, 329–365 (1967).

14.

Shanahan, W. J. , and Postle, R. , A Theoretical Analysis of the Plain Knitted Structure , Text. Res. J. 40, 656–665 (1970).

15.

Shanahan, W. J. , and Postle, R. , A Theoretical Analysis the Tensile Properties of Plain-Knitted Fabrics. Part I: The Load-Extension Curve for Fabric Extension Parallel to the Course , J. Text. Inst. 65, 200–212 (1974).

16.

Smela, E., Wearable Effect-Emitting Strain Gauge Device, US Patent No. 6360615 (2002).

17.

Wu, W. L. , Hiroyuki, H. , and Zen-ichiro, M. Computer Simulation of the Deformation of Weft-Knitted Fabrics for Composite Materials , J. Text. Inst. 85, 198-198 (1994).

18.

Xue, P. , Tao, X. M. , Yu, T. X. , Kwok, K. and Leung, S Electro-mechanical behavior and mechanistic analysis of fiber coated with electrically conductive polymer . Text. Res. J. 74, 924–937 (2004).