Rapid fabrication of curved microlens array using the 3D printing mold

In this paper, we presented a new method to directly fabricate 3D microlens array (MLA) without the pattern transfer and substrate reshaping process. Gas-assist deformed concave Polydimethylsiloxane (PDMS) film was used as the molding template. The template was fixed on the curved micro-hole array with a micro cavity during the injection molding process. The curved micro-hole array was fabricated by 3D printing in order to avoid the interference from microlens nearby. In addition, the micro-hole array is detachable, thus allowing it to be assembled onto the MLA automatically. Less than few minutes, the formation of 3D MLA can be realized by which the polymeric lens material is capable of being cured within dozens of seconds. Multi-focusing MLA was designed to reduce the defocus. And the focal length of each microlens varied according to the different diameter of micro-holes. This novel method is time-saving, cost-effective and precision. A single microlens has a radius of 250-500 μm, and the accuracy can reach 30 μm. Performance of the 3D MLA has been optically characterized. The introduction of micro-holes array can effectively reduce the crosstalk between the eyes and the influence of stray light. The curved MLA have has a FOV over 70°.