Fabrication of polymer optical diffusers by buffer-assisted ultrasonic embossing

Ultrasonic embossing and welding process is a fast and low cost manufacturing method for polymer devices in ambient temperature. More and more polymer MEMS devices, like optical devices and bio-MEMS devices are emerging in academic and engineering areas, due to the advantages of polymer materials, like low cost and easy manufacturing. In this paper, a buffer-assisted ultrasonic embossing process, using a layer of polymer film as buffer layer, was utilized to fabricate a flexible polymer optical diffuser, of which the height of the embossed microstructure is larger than the thickness of the polymer film. The optical experiment is conducted and the results verified the feasibility of the proposed buffer-assisted ultrasonic embossing process, so this buffer-assisted ultrasonic embossing process can be more polymer devices with large characteristic dimension form thin polymer films.