Fabrication Strategies for Producing Gradient Roughness Libraries
Christopher Stafford, Jun Y. Chung, Xuesong Hu, Heqing Huang
New technologies, such as flexible electronics and functional coatings systems, consist of hierarchical structures fabricated out of combinations of both soft and hard materials, with each material type lending unique properties and performance characteristics to the final integrated system. As these structures and devices become smaller and more complex, materials interfaces will transition from contributing to overall performance and reliability measures to dominating them. In particular, interfacial properties, such as adhesion, of these hierarchical structures are paramount, as the overall performance of such systems depends on the integrity of the materials interfaces within them. Surface topography plays an important role on controlling interfacial interactions. The important length scale depends on the application area and can span from the micro- to nano-scale. We present here fabrication strategies for creating gradients in roughness having continuous changes in both the dominant period and amplitude of the surface topology. A versatile method for creating roughness gradients on a different length scale is through surface wrinkling. Here, a metal film is evaporated onto the surface of a thin polymer film supported on a substrate. Heating the polymer film above Tg causes the surface to wrinkle due to the mismatch in thermal expansion of the polymer and metal layers. In this case, the length scale of roughness is controlled by the film thickness of metal and polymer layers, the heating temperature, and annealing time.
Annual Meeting of the Adhesion Society | 30th | Extended Abstracts | The Adhesion Society
, Chung, J.
, Hu, X.
and Huang, H.
Fabrication Strategies for Producing Gradient Roughness Libraries, Annual Meeting of the Adhesion Society | 30th | Extended Abstracts | The Adhesion Society, Tampa, FL, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852709
(Accessed December 4, 2023)