Bioinspired uniform illumination by vibrated sessile droplet pinned by a hydrophilic/superhydrophobic heterogeneous surface.

We introduce a strategy to generate uniform illumination. The droplet pinned by a hydrophilic/superhydrophobic heterogeneous surface is oscillated, driven by a laterally placed loudspeaker. The vibrated droplet can be considered as a tunable lens, whose focus and focus length can be real-time tuned. The tunable "lens" is presented as a device for uniform illumination by mechanical manipulation. The incident light is scattered by the vibrated droplet during oscillation, and the irradiance distribution on the image plane becomes larger and more homogenous when the droplet is at resonance. (C) 2013 Optical Society of America