Issue
EPL
Volume 77, Number 6, March 2007
Article Number 64002
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/77/64002
Published online 27 February 2007
EPL, 77 (2007) 64002
DOI: 10.1209/0295-5075/77/64002

In situ observation of stereoscopic shapes of cavities in soft adhesives

T. Yamaguchi1, 2, K. Koike1 and M. Doi1, 2

1  Department of Applied Physics, The University of Tokyo - 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
2  Japan Science and Technology Agency (JST/CREST) - Japan


received 11 October 2006; accepted in final form 26 January 2007; published March 2007
published online 27 February 2007

Abstract
By using a new visualization technique, we succeeded in the in situ observation of the stereoscopic shape of cavities formed in a thin film of soft adhesives in the debonding process of the probe-tack test. We found that the cavity shape and the interfacial fracture behavior are strongly influenced by the cross-linking density of the soft adhesives: for soft adhesives, the cavity is nearly spherical, and the fracture slows down basically due to the blunting of the cavity edge, while for hard adhesives the cavity becomes pancake-like, and the fracture is due to the coalescence of cavities at the adhesive-probe interface.

PACS
47.55.dp - Cavitation and boiling.
68.35.Np - Adhesion.

© Europhysics Letters Association 2007