Abstract: A hybrid polymer/crystal photomechanical composite material is described. The hybrid polymer/crystal photomechanical composite material includes a substrate having a top surface and a plurality of pores extending from the top surface into the interior of the substrate, and diaryl ethene (DAE) crystals disposed in each of the plurality of pores. The substrate may be made from polyethylene terephthalate (PETE). Methods for actuating the described hybrid polymer/crystal photomechanical composite material and devices incorporating therein the described hybrid polymer/crystal photomechanical composite material are also described.

Abstract: Strain-gated logic devices are important for the development of advanced flexible electronics. Using a dual-monolayer-promoted film-transfer technique, a flexible multilayer structure capable of undergoing large compressive deformation was prepared. Formation of a crease in the gap between electrodes at a geometrically tunable strain leads to formation of an electrical connection in a reversible and reproducible fashion. A strain-gated electrical switch includes at least two conductive electrodes disposed on a surface of an elastomer substrate, the at least two conductive electrodes forming a gap between the at least two electrodes in an off-state of the strain-gated electrical switch, the gap diminishing under compressive strain to form a crease, the compressive strain pressing the at least two electrodes into contact with each other in an on-state of the strain-gated electrical switch.

Abstract: Strain-gated logic devices are important for the development of advanced flexible electronics. Using a dual-monolayer-promoted film-transfer technique, a flexible multilayer structure capable of undergoing large compressive deformation was prepared. Formation of a crease in the gap between electrodes at a geometrically tunable strain leads to formation of an electrical connection in a reversible and reproducible fashion. A strain-gated electrical switch includes at least two conductive electrodes disposed on a surface of an elastomer substrate, the at least two conductive electrodes forming a gap between the at least two electrodes in an off-state of the strain-gated electrical switch, the gap diminishing under compressive strain to form a crease, the compressive strain pressing the at least two electrodes into contact with each other in an on-state of the strain-gated electrical switch.

Abstract: A wrinkled adhesive surface is prepared by swelling a laterally confined elastomer layer with a polymerizable monomer composition. Swelling the elastomer layer spontaneously produces a wrinkled surface, and the wrinkles are then stabilized by polymerizing the polymerizable monomer composition. The stabilized wrinkled surfaces prepare by the method can exhibit substantially enhanced adhesion relative to smooth surfaces of the same material. The stabilized wrinkled surfaces can also exhibit adhesion that is repeatable through many cycles of contact with and separation from another surface. The adhesive characteristics of the stabilized wrinkled surfaces can be tailored by manipulating the size of the wrinkles.

Abstract: A wrinkled adhesive surface is prepared by swelling a laterally confined elastomer layer with a polymerizable monomer composition. Swelling the elastomer layer spontaneously produces a wrinkled surface, and the wrinkles are then stabilized by polymerizing the polymerizable monomer composition. The stabilized wrinkled surfaces prepare by the method can exhibit substantially enhanced adhesion relative to smooth surfaces of the same material. The stabilized wrinkled surfaces can also exhibit adhesion that is repeatable through many cycles of contact with and separation from another surface. The adhesive characteristics of the stabilized wrinkled surfaces can be tailored by manipulating the size of the wrinkles.

Abstract: A method for assembling patterned crystalline arrays of colloidal particles using ultraviolet illumination of an optically-sensitive semiconducting anode while using the anode to apply an electronic field to the colloidal particles. The ultraviolet illumination increases current density, and consequently, the flow of the colloidal particles. As a result, colloidal particles can be caused to migrate from non-illuminated areas of the anode to illuminated areas of the anode. Selective illumination of the anode can also be used to permanently affix colloidal crystals to illuminated areas of the anode while not affixing them to non-illuminated areas of the anode.

Abstract: A method for assembling patterned crystalline arrays of colloidal particles using ultraviolet illumination of an optically-sensitive semiconducting anode while using the anode to apply an electronic field to the colloidal particles. The ultraviolet illumination increases current density, and consequently, the flow of the colloidal particles. As a result, colloidal particles can be caused to migrate from non-illuminated areas of the anode to illuminated areas of the anode. Selective illumination of the anode can also be used to permanently affix colloidal crystals to illuminated areas of the anode while not affixing them to non-illuminated areas of the anode.