Circumferential buckling and postbuckling analysis of thin films integrated on a soft cylindrical substrate with surface relief structures

As a novel tactic, controlled buckling of the stiff thin film device component on a compliant substrate with surface relief structures has been widely explored in the design and demonstration of various flexible and stretchable electronic devices. While flat substrates are mainly used in the current design and demonstration of the buckled thin film on a structured substrate, the use of cylindrical substrates presents alternative opportunities for this technique with direct applications in multifunctional catheters for the treatment of ventricular tachycardia, primary and metastatic malignancies, as well as various smart wearable devices. In this study, we will present the modeling analysis and design considerations of thin film device components on a soft cylindrical substrate with surface relief structures. By investigating the controlled circumferential buckling and postbuckling behaviors of stiff thin film integrated on a compliant cylindrical substrate with surface relief structures, the buckling/postbuckling amplitude and maximum strain in the thin film are found to depend on various material and geometric parameters. Additionally, the results predicted from the analytic model are validated by the finite element analysis, which provides a powerful toolset to inform experimental designs.