Jianfeng Zang, former MRSEC Fellow, was a Poster Award Winner at the Fall 2014 Materials Research Society meeting.
Dr. Zang studied under Professor Xuanhe Zhao, and just began a new position as a tenure-track professor at the Innovative Institute, Huazhong University of Science & Technology. Congratulations to Dr. Zhao and Dr. Zang!
Poster title: Self-Organizesd Origami of Large-Area Graphene and Graphene Papers Enables On-Demand Multifunctionalities. Dr. Zang, and Professor Xuanhe Zhao
ABSTRACT: Origami pattern, for example, Miura-ori pattern, is a periodic array of artificially and geometrically folded mountains and valleys. With the predefined creases of origami, one can fold flat sheets to create three-dimensional deformable structures. The origami-based patterns have inspired some fascinating applications, such as deployable solar panels, self-folding membranes, origami-inspired stents, Miura-ori folded metamaterials, and origami lithium-ion batteries. Patterns generated by conventional origami methods usually require predefined creases. In that way, the produced origami patterns are in macroscale. The requirement of predefined creases and macroscale size patterns greatly limited the flexibility, stretchability and controllability of this otherwise promising technology. Here, we present a novel approach that overcomes these limits, to control reversible crumpling and unfolding of large-area graphene or graphene papers by harnessing the mechanical instabilities using soft materials. We transfer a large-area graphene or graphene paper on an elastomer substrate that is either uniaxially or biaxially stretched to 3~5 times of its original dimension. Self-organized origami patterns, such as wrinkles, delaminated buckles, or localized ridges, develop in graphene or graphene papers when the substrate is simply relaxed uniaxially or biaxially. The origami patterns of graphene or graphene papers can be unfolded by stretching the substrate back. Graphene nanocomposites or surfaces of the graphene or graphene papers exhibit an unprecedented combination of merits including high stretchability (e.g., linear strain ~400%, areal strain ~1500%), reliability (e.g., over 1000 stretch/relax cycles), transparent and conductive electrodes, on-demand superhydrophobicity, supercapacitors (e.g., specific capacitance ~196 F g-1) and artificial muscle actuators (~100% areal strain). Our work not only reveals new modes of instabilities in graphene and graphene papers for studying fundamental properties of highly deformed and patterned graphene / grpahene papers in large-area, but also creates electrodes and coatings with unprecedented combined properties and tunability and provides a powerful tool for studying graphene-based nanocomposites and biomedical devices with changeable “on demand” functions.