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An improved process has been developed for tile efficient fabrication of a microlens array with high fill factor and controllable configuration. The microlens mold for patterning transfiwmatinn was fabricated by using tile processes of glass wet etching, nickel electroplating, photoresist spin coating, and encapsulated air heating. The convex microlens shape resulted from the photoresist compressed by the thermal expansion of sealed air to form a semispherical shell. By adjusting the heating temperature and the sealed air volume, the curvature and size of the shell arc controllable. In addition, the microlens mold or piano-convex micromirror can be fabricated by depositing a metal film on the surface profile of swelled photoresist. An analytical model was established to prediet the surface profile of a single microlens and was experimentally verified. A typical microlens mold made from nickel with different fill factors and various configurations was also fabricated and characterized. The polysiloxine microlens array was also fabricated by mold pressuring, and its optical properties were measured to identify the focusing capability. Experimental results reveal that various configurations of microlens array could be formed, such as semielliptical and M-character, by defining the pitch sizes of via holes. High fill factors approaching 100% can also be achieved. The fabrication provides an effective way to manufacture a microlens mold to serve as the master element for replication. Index Terms--Configuration, fill factor, heating, microlens array, photoresist.

Abstract Background The Taiwan government adopted National Health Insurance (NHI) in 1995, providing universal health care to all citizens. It was financed by mandatory premium contributions made by employers, employees, and the government. Since then, the government has faced increasing challenges to control NHI expenditures. The aim of this study was to determine trends in the provision of dental services in Taiwan after the implementation of global budgeting in 1998 and to identify areas of possible concern. Methods This longitudinal before/after study was based on data from the National Health Insurance Research Database from 1996 to 2001. These data were subjected to logistic regression analysis. Linear regression analysis was used to examine changes in delivery of specific services after global budgeting implementation. Utilization of hospital and clinic services was compared. Results Reimbursement for dental services increased significantly while the number of visits per patient remained steady in both hospitals and clinics. In hospitals, visits for root canal procedures, ionomer restoration, tooth extraction and tooth scaling increased significantly. In dental clinics, visits for amalgam restoration decreased significantly while those for ionomer restoration, tooth extraction, and tooth scaling increased significantly. After the adoption of global budgeting, expenditures for dental services increased dramatically while the number of visits per patient did not, indicating a possible shift in patients to hospital facilities that received additional National Health Insurance funding. Conclusions The identified trends indicate increased utilization of dental services and uneven distribution of care and dentists. These trends may be compromising the quality of dental care delivered in Taiwan.