(593a) Shape Memory Assisted Contact Printing in Nanoscience and Electronics

Over the past two decades, contact transfer printing has evolved into a viable manufacturing technology that can deposit and pattern various organic, polymeric and inorganic ink materials with micro- and nano-scale precision. Contact printing relies on the elastomeric stamp that forms an adhesive and conformal contact with the ink layer during the ink pickup, and on the interfacial fracture of the ink-stamp interface during the ink transfer. Contact printing is inherently amenable to replicate large-area patterns on flat or curvilinear substrates, and it has potential to evolve into a universal platform for large-area, parallel deposition of multiple types of materials at the sub-micrometer length scale. However, the key to enabling such manufacturing is to establish clean and reliable methods for controlling interfacial adhesion and fracture mechanics during the ink pickup and release.

In the past, we have demonstrated that the adhesive stamp-ink interactions can be controlled by the chemical composition and stiffness of the polymeric stamps. For example, the surface energy of the polymers can be controlled chemically, producing stamps with tunable polarity. As a consequence, high and low surface energy stamps can be used to pattern a variety of electronic materials with ~100nm resolution and high uniformity. More recently, we have shown that modulation of the interfacial adhesion can be achieved with stamps made of shape-memory polymers that can change their contact area with inks using external stimuli. We have demonstrated that by modulating the stamp adhesion using thermo-mechanical cycles, we can pick up and deposit multicomponent films of inorganic and organic electronic materials from the donor substrate to the receiver surface. Our approach permits patterning of multilayered stacks of organic/inorganic thin films with <1µm resolution and high uniformity. We envison, that the developed method will find numerous applications in nanoscience and electronics. For example, we are currently adapting our technology to pattern complete pixels of the µ-LED devices with sub-micrometer resolution using a unified set of materials and printing conditions.