Droplet-based lateral tunable optofluidic microlens array with pneumatic control

Abstract

We report on a droplet-based, in situ formed tunable cylindrical microlens array in microchannels. The deionized water microlenses are formed via liquid-air interfaces of liquid droplets at T-shaped junctions of octadecyltrichlorosilane (OTS) treated polymerized isobornyl acrylate [poly(IBA)] microchannels, and their focal length can be tuned individually by pneumatic manipulation. These microlenses possess low spherical aberrations. Gravity, which affects the shape of the liquid microlenses, is considered in the design. Fluorescence enhancement for potential lab-on-a-chip applications is also demonstrated using such microlens array.