Fabrication and characterization of microlens array manufactured from microfluidic chip

The paper presents a novel manufacturing process for microlens arrays (MLA). This process used micro machining, double-sided PDMS casting, and plasma bonding to create a hybrid microfluidic chip for manufacturing an MLA on a PDMS substrate. Compared to other reported methods for MLA, this method is rapid, cost-efficient, and capable of manufacturing MLA with various physical dimensions, including sag height and curvature, on a single substrate. The fundamental idea of this method is to deform the PDMS membrane by changing the hydraulic pressure inside the microchannel. Experiment were realized to understand the relationship between the hydraulic pressure inside the microchannel and the deformation of PDMS. And to characterize the uniformity of the MLA, an automatic optical system was built to measure the focal length and curvature of each microlens.