Hostname: page-component-848d4c4894-cjp7w Total loading time: 0 Render date: 2024-06-27T01:04:16.421Z Has data issue: false hasContentIssue false

Crack prevention of highly bent metal thin films in woven electronic textiles

Published online by Cambridge University Press:  11 August 2011

T. Kinkeldei*
Affiliation:
Wearable Computing Laboratory, Federal Institute of Technology Zurich, 8092 Zurich, Switzerland
K. Cherenack
Affiliation:
Wearable Computing Laboratory, Federal Institute of Technology Zurich, 8092 Zurich, Switzerland
C. Zysset
Affiliation:
Wearable Computing Laboratory, Federal Institute of Technology Zurich, 8092 Zurich, Switzerland
N.C. Woo
Affiliation:
Laboratory for Nanometallurgy, Federal Institute of Technology Zurich, 8093 Zurich, Switzerland
G. Tröster
Affiliation:
Wearable Computing Laboratory, Federal Institute of Technology Zurich, 8092 Zurich, Switzerland
Get access

Abstract

Recent smart textile fabrication methods that are aimed at increasing the integration of electronics with textiles have involved fabricating micro-electronic components directly at the yarn level. Our approach to creating smart textiles is to fabricate thin-film devices and interconnects on plastic strips to create ‘e-fibers’ and weave them into a textile using a commercial weaving machine. e-Fibers are exposed to bending radii as small as 165 μm during weaving. If patterned interconnect lines and device layers on the surface of the e-fiber are not designed correctly, they will crack due to the high strain and lose their electronic functionality. Brittle sensor and transistor device layers may be protected locally using rigid encapsulation materials, but cracking remains an issue for long metal interconnect lines which require flexibility. We investigated two strain-control methods to prevent the thin-film interconnect lines from cracking during weaving: (1) patterning the metal interconnect lines with a geometric design to slow propagation and merging of cracks and (2) encapsulation of interconnect lines to shift the deposited films to the neutral plain of the substrate. The mechanical behavior of interconnect lines exposed to tensile bending was studied by measuring the change in interconnect resistance versus bending radii ranging from 5 mm to 50 μm. The critical bending radius, XC, defined as the radius at which the normalized interconnect resistance changes to 1.1 (indicating the onset of film rupturing) was 150 μm for standard interconnect lines. Patterned interconnect lines had a radius XC of 115 μm while encapsulated interconnect lines never reached this critical bending radius and showed a maximum resistance change of 1.02 at 100 μm. These results show that it is possible to design interconnect lines with reduced cracking behavior when exposed to high strain during commercial weaving.

Type
Research Article
Copyright
© EDP Sciences, 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amft, O., Tröster, G., IEEE Pervas. Comput. 8, 62 (2009)CrossRef
Bächlin, M., Plotnik, M., Roggen, D., Meidan, I., Hausdorff, J.M., Giladi, N., Tröster, G., IEEE Trans. Inf. Technol. Biomed. 14, 436 (2010)CrossRef
Locher, I., Kirstein, T., Tröster, G., Temperature profile estimation with smart textiles, in Proc. of 1st International Scientific Conference Ambience 05, Tampere, Finland, 2005, pp. 18
Meoli, D., May-Plumlee, T., JTATM 2, 1 (2002)
Lee, J.B., Subramanian, V., Organic transistors on fiber: a first step towards electronic textiles, in IEEE International Electron Devices Meeting, 2003. IEDM’03 Technical Digest, 2003, pp. 8.3.18.3.4 Google Scholar
Hamedi, M., Forchheimer, R., Inganäs, O., Nat. Mater. 6, 357 (2007)CrossRef
Wagner, S., Bonderover, E., Jordan, W.B., Sturm, J.C., Int. J. High Speed Electron. Syst. 12, 391 (2002)CrossRef
Jafari, R., Bajcsy, R., Glaser, S., Gnade, B., Sgroi, M., Sastry, S., Platform design for health-care monitoring applications, in Proc. of 2007 Joint Workshop on High Confidence Medical Devices, Software, and Systems and Medical Device Plug-and-Play Interoperability, (IEEE Computer Society, Washington, DC, USA, 2007), pp. 8894 Google Scholar
Bonderover, E., Wagner, S., IEEE Electron Device Lett. 25, 295 (2004)CrossRef
Cherenack, K., Kinkeldei, T., Zysset, C., Tröster, G., IEEE Electron. Device Lett. 31, 740 (2010)CrossRef
Lu, N., Wang, X., Suo, Z., Vlassak, J., Appl. Phys. Lett. 91, 221909 (2007)CrossRef
Xiang, Y., Li, T., Suo, Z., Vlassak, J.J., Appl. Phys. Lett. 87, 161910 (2005)CrossRef
Zhu, X.F., Zhang, B., Gao, J., Zhang, G.P., Scr. Mater. 60, 178 (2009)CrossRef
Li, Y., Wang, X.S., Meng, X.K., Appl. Phys. Lett. 92, 131902 (2008)CrossRef
Mandlik, P., Lacour, S.P., Li, J.W., Chou, S.Y., Wagner, S., IEEE Electron Device Lett. 27, 650 (2006)CrossRef
Christiaens, W., Loeher, T., Pahl, B., Feil, M., Vandevelde, J. Vanfleteren, Circuit World 34, 3 (2008)CrossRef
Verebelyi, D., Harley, E., Scudiere, J., Otto, A., Schoop, U., Thieme, C., Rupich, M., Supercond. Sci. Technol. 16, 1158 (2003)CrossRef
Woo, N.C., Cherenack, K., Tröster, G., Spolenak, R., Appl. Phys. Lett. A 100, 281 (2010)CrossRef
Lin, Y.S., Liu, H.M., Thin Solid Films 516, 1773 (2008)CrossRef
Suo, Z., Ma, E.Y., Gleskova, H., Wagner, S., Appl. Phys. Lett. 74, 1177 (1999)CrossRef
Han, L., Song, K., Mandlik, P., Wagner, S., Appl. Phys. Lett. 96, 042111 (2010)CrossRef
Li, T., Suo, Z., Int. J. Solids Struct. 44, 1696 (2007)CrossRef