(305g) Nanocomposite Kirigami As Strain-Tunable Optical Gratings

Authors: 
Wang, X., University of Michigan
Kotov, N. A., University of Michigan
Nanocomposites with kirigami-inspired microstructures can create exciting opportunities for advanced technologies, ranging from stretchable electronics to adaptive optics. In kirigami techniques, patterned cuts are introduced in thin film composites for reducing strain concentration under macroscopic deformation and/or guiding formation of complex structures from simple 2D elements. Here we show that microscale kirigami of nanocomposites from stiff plastics, metals and carbon nanotubes can yield highly stretchable and tunable optical diffraction gratings. These reconfigurable optical gratings with over a 100% range of period tunability enable critical capabilities in beam steering and optical power modulation. The angular range of beam steering can be as large as 6.5 degrees for 635nm laser beam as compared to ~1 degree in previously reported surface-grooved elastomer gratings and ~0.02 degree in MEMS gratings. The versatility of the kirigami patterns, the diversity of the available nanocomposite materials, and their advantageous mechanical properties of the foundational materials open the path for engineering of advanced reconfigurable optical devices.