Submicrometer Patterning by Laser Direct-writting and its Application to a Microfluidic Coulter Counter

• Main Authors: Yi-Chen Lin, 林易貞
• Other Authors: Jyh-Jong Sheen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/60085721392916226925

碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 98 === Non-periodic nanopatterning by laser direct-writing has been usually carried out by near-field ablation. This work describes a simple far-field method to fabricate nanopatterns beyond diffraction limit. An approach dubbed subtractive LIBWE was used. In this approach the laser induced backside wet etching (LIBWE) process was used to ablate ITO layer with substrate mounted on a precision nano-stage. For the ablated region, the minimal width is determined by diffraction limit. In current setup a 10X objective lens was used (N.A. 0.25).Using 532 nm Q-switched laser, the diffraction limit is calculated to be (~0.61/N.A.) ~ 1.3 micrometer. The width of the remaining ITO film is not determined optically but by the precision of the nano-stage that is used to move the substrate. Using this subtractive LIBWE process, strips of width from 250nm to 350 nm were obtained by laser direct-writing. The obtained width is well below the diffraction limit of ~1.3 micrometer. We have successfully used economic green laser in the difference process for preparing micro-fluid chip and ITO electrodes application for Coulter counter. The testing of the ITO electrode on micro fluidic device using different size particle has demonstrated the ability to recognize particle size. The experimental results described the ITO electrodes application for Coulter counter has good sensibility and has wide frequency range detection area.