Studying the influence of the photopolymer material properties to the creation of MLAs with using digital light processing (DLP) stereolithography printing (SLA)

Microlens arrays (MLAs) is an important optical component used in various emerging fields, and applying grayscale digital masks and defocusing method to digital light processing (DLP) stereolithography (SLA) 3D printing for rapid fabrication of MLAs within 1 s was successfully demonstrated previously. To further improve the performance of printed MLAs competitive to the commercial MLAs, a new photopolymer (TP01K9) was used herein and multiple experiments were conducted to characterize the printed MLAs. Experiment results clearly show that: (1) the material properties of photopolymer, including forming characteristic, mechanical strength, and Abbe number, were critical and deeply influenced the performance of MLAs, (2) the image resolution was improved to 58.7 lp/mm, which is very competitive or superior than the commercial plastic MLAs with reso-lution of 48.8 lp/mm, (3) defocus method significantly reduced the average surface roughness (Sa) of the printed MLAs to 80 nm, which is critical to the image resolution, (4) with photopolymer of TP01K9, the MLA with a 10 x 10 array, lens pitch of 120 & mu;m, and lens diameter of 60 & mu;m was successfully manufactured.

Automated summary

By using a new photopolymer, grayscale digital masks and defocusing method were successfully applied to DLP-SLA 3D printing for rapid fabrication of microlens arrays (MLAs) with improved performance compared to commercial MLAs. Experimental results show that: (1) the material properties of photopolymer greatly influence the performance of MLAs; (2) the image resolution was improved to 58.7 lp/mm, surpassing the commercial plastic MLAs with a resolution of 48.8 lp/mm; (3) defocus method significantly reduced the surface roughness of printed MLAs, critical for image resolution; (4) MLAs with a 10 x 10 array, lens pitch of 120 μm, and lens diameter of 60 μm were successfully manufactured using TP01K9 photopolymer.