Localization and length-scale doubling in disordered films on soft substrates
Matthew R Semler1, John M Harris, Andrew B Croll
1Department of Physics, North Dakota State University, Fargo, North Dakota 58108, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 16, 2013
Summary
Researchers studied wrinkling and folding in disordered thin films on soft substrates. Structural disorder influences these instabilities, impacting material behavior and guiding theoretical models.
Area of Science:
- Materials Science
- Physics of Soft Matter
- Thin Film Mechanics
Background:
- Thin films on soft substrates are prone to wrinkling and folding instabilities.
- Structural disorder in films can significantly alter mechanical responses.
- Understanding these phenomena is crucial for designing advanced materials and devices.
Purpose of the Study:
- To experimentally investigate wrinkling and folding in diverse disordered thin film systems.
- To elucidate the role of structural disorder in thin film instabilities.
- To provide insights for developing theoretical models of thin film mechanics.
Main Methods:
- Experimental examination of three distinct disordered film types: diblock copolymers, glassy polymers, and single-wall carbon nanotubes.
- Utilizing polydimethylsiloxane (PDMS) substrates for controlled mechanical testing.
- Analysis of film behavior under varying strain conditions.
Main Results:
- All three film systems demonstrated localization and length-scale doubling at small strains.
- A physical argument based on stress correlation and localization sites qualitatively explains these observations.
- Observed phenomena are relevant across various disordered film/soft substrate systems.
Conclusions:
- Structural disorder plays a critical role in dictating thin film wrinkling and folding behaviors.
- The findings offer a foundation for refining theoretical models of thin film instabilities.
- Insights are applicable to a wide range of disordered films on soft elastic materials.
