Innovative rapid replication of microlens arrays using electromagnetic force-assisted UV imprinting

This paper reports an innovative method for the rapid replication of microlens arrays. In using electromagnetic force to press uniformly a ferromagnetic soft mold written with microlens array cavity into a UV-curable resin on a glass substrate, a polymer microlens array can be rapidly fabricated. In this study, an electromagnetic force-assisted imprinting facility with UV exposure capacity has been designed, constructed and tested. The 300 x 300 microlens array with a diameter of 150 mu m and a pitch of 200 mu m is successfully produced. Scanning electron microscopy (SEM) and optical observations confirm that the polymer microlens arrays are produced without defects or distortion and with good pattern fidelity over a large area. The microlens arrays have a smooth surface and fine focusing function. This technique shows great potential for the efficient replication of the microlens array at room temperature and with low pressure on large substrates with high productivity and low cost.