Fabrication of Precision Micrograting on Resin Substrate Utilizing Ultrasonic-Assisted Molding
Sergey Bolotov, Ryuichi Kobayashi, Keita Shimada,
Masayoshi Mizutani, and Tsunemoto Kuriyagawa
Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki, Aoba, Aoba-ku, Sendai 980-8579, Japan
Molding is an effective and efficient approach to producing highly functional optical elements with complex shapes. However, edge sharpness is a serious problem with molded microstructures. An Ultrasonic-Assisted Molding (UAM) device was developed to improve shape transferability. First, basic experiments showed that UAM induced a maximum temperature increase of 3.2°C for a polycarbonate substrate with a starting temperature of 170°C, and the stick-slip phenomenon was not observed with ultrasonic vibration. Second, UAM and conventional molding simulation models were constructed to compare the transferability of a microgroove; ultrasonic superimposed press movement demonstrated the highest transferability. Finally, micrograting was fabricated using UAM and conventional molding, and the UAMmicrograting had better transferability with a 30-smolding time. Therefore, UAM may be an effective process for reducing molding time.
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