1st International Conference on on Optics, Photonics and Lasers (OPAL' 2018) 9-11May 2018, Barcelona, Spain Shape Memory Molding: A New Method for Fabricating Polymer Optics W. D. Liu 1 and L.C. Zhang 1 1 Laboratory for Precision and Nano Processing Technologies, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, 2052 Australia Tel.: +61 2 93856078, fax: +61 2 96631222 E-mail:
[email protected] Summary: This paper reports a new molding technique for fabricating polymer optics based on the shape memory property of poly(methyl methacrylate) (PMMA). Different from traditional thermoforming techniques that require expensive and time-consuming moulding process, this technique only needs a programmed PMMA sample, a mold, and a furnace. Particularly, in this paper a programmed PMMA sample was prepared via high-temperature compression; a mold with micro-lens array cavities was fabricated by an ultra-precision machining center; shape memory molding was conducted at high temperature without applying any external force. It was found that after the programming process, significant residual stress was stored in the PMMA sample, which can be characterized by a polariscope. During the shape memory moulding process, the residual stress could be released, and the sample expanded and filled the die cavities. The profile of the moulded micro-lens arrays was charactered by a white light interferometer system. Keywords: Shape memory molding, polymer optics, residual stress, PMMA, microlens array 1. Introduction transition temperature is 105 ˚C. Circular samples with a thickness of 2.6 mm and a diameter of 7 mm Polymer optics are widely used in optical devices were cut from the raw material plate and polished by due to their low cost of materials, high production #2000 sandpaper.