With increasing demand for miniaturization of optoelectronics, the microlens array has attracted significant attention and become an important micro-optics device widely used in compact imaging, sensing, optical communication and others. Typically, microlens array consists of multiple micron-sized lenses with optical surface smoothness and superior uniformity, which increases the requirement for machining precision.
Now researchers from the Singapore University of Technology and Design (SUTD) and Southern University of Science and Technology (SUSTech) in Shenzhen, China, have proposed an approach that integrates oscillation-assisted digital light processing (DLP) 3D printing with grayscale UV exposure. The combination is said by the partners to create “ultrafast and flexible fabrication of microlens arrays with optical surface smoothness.”
The work has been published in Applied Materials & Interfaces in paper entitled Ultrafast three-dimensional printing of optically smooth microlens arrays by oscillation assisted digital light processing. Associate Prof Qi Ge from SUSTech commented, “3D printing of small geometries with optical surface smoothness is a big challenge. In our approach, the computationally-designed grayscale patterns are used to realize microlens profiles on a single UV exposure, which removes the staircase effect existing in the traditional layer-by-layer 3D printing method. The projection lens oscillation is applied to further eliminate the jagged surface formed due to the gaps between discrete pixels.”