fabrication of three-dimensional objects from the prgrammed two-dimensional structures

Abstract

Combining the physical principle of actuators with the basic concept of photonic crystals, color-tunable three-dimensional photonic actuators were successfully fabricated. By controlling the d-spacings and the refractive index contrasts of the self-assembled 3D colloidal photonic crystals, colors of the photonic actuators were manipulated. Various shapes of these 3D actuating objects were constructed by transforming the programmed 2D structures via bending, twisting and folding mechanisms. Scroll photonic actuators had been first demonstrated by bending the traditional 2D cantilever structure. By breaking the symmetry of a cantilever structure perpendicular to its long axis, polypeptide-/DNA-like 3D helical photonic actuators were obtained from the programmed 2D structure via twisting processes. Both left- and right-handed scrolls and helices with various colors can be achieved by changing the polarity of solvents.