Wrinkling of thin films on compliant substrates. Rui Huang Center for Mechanics of Solids, Structures and Materials The University of Texas at Austin. Au films on PDMS (Bowden et al., Nature 393, 146, 1998). SiO 2 on Si (Courtesy of David Cahill). Wrinkling of thin films.
Center for Mechanics of Solids, Structures and Materials
The University of Texas at Austin
Nonlinear effect: large deflection of the film
Energy minimization leads to the energetically favored wave number and the corresponding equilibrium amplitude:
The energetically favored mode is independent of the compressive strain.
Kinetics effect: growth rate depends on the driving force
Other nonlinear effects: plasticity, large deformation of substrate
Rigid substrateKinetically Constrained Equilibrium Wrinkles
Infinitely many:each wavelength ( > c) has an equilibrium state
Energetically unstable: longer wavelength lower energy
Kinetically constrained: flow is very slow near the equilibrium state
Huang and Suo, J. Appl. Phys. 91, 1135 (2002).
A 200m by 200m SiGe island on BPSG annealed for 90 minutes at 790°C.
Huang et al., Acta Mechanica Sinica 18, 441, (2002)
Amplitude growth per cycle:
Huang et al., in preparation.
Zhigang Suo (Harvard University)
Zhenyu Huang (Harvard University)
Haizhou Yin (Princeton University)
James C. Sturm (Princeton University)
Jim Liang (Intel Corp.)
Se Hyuk Im (University of Texas-Austin)