Delamination-based measurement and prediction of the adhesion energy of thin film/substrate interfaces

With the rapid emerging of two-dimensional (2D) micro/nanomaterials and their applications in flexible electronics and microfabrication, adhesion between thin film and varying substrates is of great significance for fabrication and performance of micro devices and for the understanding of the buckle delamination mechanics. However, the adhesion energy remains to be difficult to be measured, especially for compliant substrates. We propose a simple methodology to deduce the adhesion energy between a thin film and soft substrate based on the successive or simultaneous emergence of wrinkles and delamination. The new metrology does not explicitly require the knowledge of the Young's modulus, Poisson's ratio, and thickness of the 2D material, the accurate measurement of which could be a challenge in many cases. Therefore, the uncertainty of the results of the current method is notably reduced. Besides, for cases where the delamination width is close to the critical wrinkle wavelength of the thin film/substrate system, the procedure can be further simplified. The simple and experimentally easy methodology developed here is promising for determining/estimating the interface adhesion energy of a variety of thin film/soft substrate systems. Copyright © 2017 by ASME.