Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Fabrication of PDMS Lens Using Photolithography and Water Droplet Mold

사진식각공정과 물방울 형틀을 이용한 PDMS 렌즈 제작

  • 김진영 (포항공과대학교 기계공학과) ;
  • 성중우 (포항공과대학교 기계공학과) ;
  • 조성진 (포항공과대학교 기계공학과) ;
  • 김철홍 (포항공과대학교 전자전기공학과) ;
  • 임근배 (포항공과대학교 기계공학과)
  • Received : 2013.08.14
  • Accepted : 2013.09.06
  • Published : 2013.09.30
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Abstract

We developed a novel fabrication method of polydimethylsioxane (PDMS) lens, which can easily control the shapes of the lens using soft lithography with common photolithography and water droplet molding. A mold for PDMS lens was prepared by patterning of hydrophobic photoresist on the hydrophilic substrate and dispensing small water droplets onto the predefined hydrophilic patterns. The size of patterns determined the dimension of the lens and the dispensed volume of the water droplet decided the radius of curvature of the PDMS lens independently. The water droplet with photoresist pattern played a robustly fixed mold for lens due to difference in wettability. The radius of curvature could be calculated theoretically because the water droplets could approximate spherical cap on the substrate. Finally, concave and convex PDMS lenses which could reduce or magnify optically were fabricated by curing of PDMS on the prepared mold. The measured radii of the fabricated PDMS lenses were well matched with the estimated values. We believe that our simple and efficient fabrication method can be adopted to PDMS microlens and extended to micro optical device, lab on a chip, and sensor technology.

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References

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