(109e) Soft film delamination from dynamic wrinkling substrates

The design of active foulant-resistant surfaces possesses many potentials for application across industry. The Velankar lab has examined wrinkling bilayers, founded on the basis of compressive thin film mechanics, on their ability to remove topically bonded materials. The wrinkling surfaces were comprised of an elastic rubber substrate and a stiff thin film of cyanoacrylate. Polydimethylsiloxane (PDMS) was used as a mock foulant which was modeled as a continuous patch. Wrinkle wavelength was directly proportional to the thin film thickness and PDMS patches were capable of being cast and cured; these methods allowed for length parameters to be preferentially adjusted. Past work was dedicated to understanding the physical fundamentals of delamination when varying the length scale between foulant layer thickness and wrinkling wavelength, (t/λ). Experimental results were compared to an ANSYS simulation, which predicted that the critical strain, the strain required to initiate delamination, became independent of foulant thickness when an adhered foulant was comparatively thick to the wavelength, whereas critical strain developed a steep inverse dependency on foulant layer thickness when it was comparatively thin. Substrate strain was realizable once motion tracking data was processed. Experiments qualitatively displayed edge delamination from propagating wrinkles while exhibiting little deformation of the patch surface, corresponding to the thick patch regime delamination mechanism. Further work is necessary to compare the simulation over the full range of the experimental length scale, including the thin patch regime.