In situ observation of stereoscopic shapes of cavities in soft adhesivesT. 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
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.
47.55.dp - Cavitation and boiling.
68.35.Np - Adhesion.
© Europhysics Letters Association 2007