Confined thin film wrinkling on shape memory polymer with hybrid surface morphologies

Abstract

With appropriate stimuli, such as heat, humidity, or magnetic field, shape memory polymers (SMPs) can recover to their original shapes from temporary, programmed states. Using thermal responsive SMPs as substrates, we demonstrate a simple method to realize hybrid surface morphologies through confined thin film wrinkling in localized areas. The bilayer system was fabricated by depositing a layer of aluminum thin film on top of a SMP substrate programmed with a tensile strain. After the system was heated by a heating wire, hybrid wrinkling patterns were formed in a confined circular area around the heat source, with an inner spoke pattern and an outer ring pattern. Wrinkling patterns showed good symmetry, and the size of the wrinkling area can be tuned by controlling the heat input. This study offers a simple but effective approach to fabricate hybrid morphological features in micro-scale.