title: Manufacture of dual-side surface-relief diffusers with various cross angles using ultrasonic embossing technique.
abstract: This paper reports a simple and effective ultrasonic embossing method which enables the rapid fabrication of dual-side surface-relief plastic diffusers with various cross angles. Metallic master molds bearing microstructures are fabricated using a tungsten carbide turning machine. A 1500-Watt ultrasonic vibrator with an output frequency of 20 kHz was used to replicate the microstructure onto 1 mm thick PMMA and PET films in the experiments. During ultrasonic embossing, the ultrasonic energy is converted into heat through intermolecular friction at the master mold/plastic plate interface due to asperities to melt the thermoplastic at the interface and thereby to replicate the microstructure. Under the proper processing conditions, high-performance dual-sided plastic diffusers of various cross-angles can be successfully fabricated. The proposed method shows great potential for fast fabrication of micro-optical components due to its simplicity and versatility.
authors.affiliation: Department of Mechanical Engineering Chang Gung University, Tao-Yuan 333, Taiwan. shihjung@mail.cgu.edu.tw
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Liu
authors.forename: Yu-Chin
authors.initials: YC
authors.lastname: Huang
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D008567:Membranes, Artificial; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013010:Sonication / Q000379:methods*
chemical_list: D008567:Membranes, Artificial