We present a method to fabricate freestanding and movable photonic microstructures by photopolymerization in a zirconium-based sol-gel hybrid resist with femtosecond laser three-dimensional (3D) direct writing. The freestanding microstructures exhibit much less distortion than the conventional structures attached to substrates, especially when made at close to the photopolymerization threshold. A few percent shrinkage which exists rescales the structure and it can lead to the shift of the photonic stop band toward shorter wavelengths. Fabrication of freestanding and freely movable (in micro-fluidic environment) 3D microstructures realizes a simple approach to quantitatively study the shrinkage of photopolymers and to improve the resolution. 3D-movable micro-optical elements with designed photonic properties and micro-devices have potential in opto-fluidics and opto-micro-mechanical applications based on laser trapping and manipulation.
Journal of Micromechanics and Microengineering,
Vol. 20, no. 3 (Mar 2010), article no. 035004