| AVS 59th Annual International Symposium and Exhibition | |
| Electronic Materials and Processing | Wednesday Sessions |
| Session EM+TF-WeM |
| Session: | Hybrid Electronic Materials and Interfaces |
| Presenter: | J.L. Yague, Massachusetts Institute of Technology |
| Authors: | J.L. Yague, Massachusetts Institute of Technology J. Yin, Massachusetts Institute of Technology D. Eggenspiele, Massachusetts Institute of Technology M.C. Boyce, Massachusetts Institute of Technology K.K. Gleason, Massachusetts Institute of Technology |
| Correspondent: | Click to Email |
Formation of wrinkles through buckling of a stiff coating on a compliant substrate can be found very commonly in nature. For instance, the epidermal ridges, which form our fingerprints, show a very unique pattern due to out-of-plane bending of the epidermis. The use of wrinkling to obtain patterned surfaces has become increasingly significant for a wide range of applications, such as: microfluidic, tunable wettability, stretchable electronics, photonics or anti-fouling surfaces. In this work, we demonstrate the ability to obtain labyrinth and herringbone patterns using a 2D stretching-releasing approach.
On top of a compliant substrate, an acrylate-based polymer is deposited by initiated chemical vapor deposition (iCVD). iCVD is a solvent-free method that yields a conformal thin coating on virtually any substrate, giving a controllable thickness and tunable structural, mechanical, thermal, wetting, and swelling properties. Monomer together with an initiator is introduced into a reactor chamber under vacuum, where the initiator is decomposed over resistively heated filaments to obtain radicals. Radicals and monomer are then adsorbed on a surface, which is kept at a controlled temperature to promote adsorption, to yield the polymer by the classical free-radical mechanism. Here, deterministic herringbone patterns are achieved through wrinkling of the polymer thin film. Furthermore, a simplified theoretical model is developed to predict the geometry of the ordered herringbone pattern. Depending on the experimental conditions is possible to control the features of such pattern. We report, for first time, the obtention of herringbone patterns with a jog angle lower than 90º. Finally, this method also provides a tool to determine the Young’s modulus of the films based only on the characteristic wavelengths of the pattern.