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Optics Letters

Optics Letters


  • Editor: Xi-Cheng Zhang
  • Vol. 39, Iss. 17 — Sep. 1, 2014
  • pp: 5162–5165

Fine-tuned grayscale optofluidic maskless lithography for three-dimensional freeform shape microstructure fabrication

Suk-Heung Song, Kibeom Kim, Sung-Eun Choi, Sangkwon Han, Ho-Suk Lee, Sunghoon Kwon, and Wook Park  »View Author Affiliations

Optics Letters, Vol. 39, Issue 17, pp. 5162-5165 (2014)

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This article presents free-floating three-dimensional (3D) microstructure fabrication in a microfluidic channel using direct fine-tuned grayscale image lithography. The image is designed as a freeform shape and is composed of gray shades as light-absorbing features. Gray shade levels are modulated through multiple reflections of light in a digital micromirror device (DMD) to produce different height formations. Whereas conventional photolithography has several limitations in producing grayscale colors on photomask features, our method focuses on a maskless, single-shot process for fabrication of freeform 3D micro-scale shapes. The fine-tuned gray image is designed using an 8-bit grayscale color; thus, each pixel is capable of displaying 256 gray shades. The pattern of the UV light reflecting on the DMD is transferred to a photocurable resin flowing through a microfluidic channel. Here, we demonstrate diverse free-floating 3D microstructure fabrication using fine-tuned grayscale image lithography. Additionally, we produce polymeric microstructures with locally embedded gray encoding patterns, such as grayscale-encoded microtags. This functional microstructure can be applied to a biophysical detection system combined with 3D microstructures. This method would be suitable for fabricating 3D microstructures that have a specific morphology to be used for particular biological or medical applications.

© 2014 Optical Society of America

OCIS Codes
(220.0220) Optical design and fabrication : Optical design and fabrication
(220.3740) Optical design and fabrication : Lithography
(220.4000) Optical design and fabrication : Microstructure fabrication

ToC Category:
Optical Design and Fabrication

Original Manuscript: June 13, 2014
Revised Manuscript: July 23, 2014
Manuscript Accepted: July 23, 2014
Published: August 27, 2014

Suk-Heung Song, Kibeom Kim, Sung-Eun Choi, Sangkwon Han, Ho-Suk Lee, Sunghoon Kwon, and Wook Park, "Fine-tuned grayscale optofluidic maskless lithography for three-dimensional freeform shape microstructure fabrication," Opt. Lett. 39, 5162-5165 (2014)

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  1. M. J. Madou, Fundamentals of Microfabrication (CRC Press, 1997).
  2. C. Chihchen, D. Hirdes, and A. Folch, Proc. Natl. Acad. Sci. USA 100, 1499 (2003).
  3. A. J. Chung, D. R. Gossett, and D. D. Carlo, Small 9, 685 (2013). [CrossRef]
  4. D. D. Carlo, N. Aghdam, and L. P. Lee, Anal. Chem. 78, 4925 (2006). [CrossRef]
  5. J. S. Park, S. H. Song, and H. I. Jung, Lab Chip 9, 939 (2009). [CrossRef]
  6. S. E. Chung, W. Park, S. Shin, S. A. Lee, and S. Kwon, Nat. Mater. 7, 581 (2008). [CrossRef]
  7. J. A. Rogers, K. E. Paul, R. J. Jackman, and G. M. Whitesides, Appl. Phys. Lett. 70, 2658 (1997). [CrossRef]
  8. S. Maruo, O. Nakamura, and S. Kawata, Opt. Lett. 22, 132 (1997). [CrossRef]
  9. H. B. Sun and S. Kawata, NMR/3D Analysis/Photopolymerization (Springer, 2004).
  10. S. E. Chung, W. Park, H. Park, K. Yu, N. Park, and S. Kwon, Appl. Phys. Lett. 91, 041106 (2007). [CrossRef]
  11. D. Dendukuri, D. C. Pregibon, J. Collins, T. A. Hatton, and P. S. Doyle, Nat. Mater. 5, 365 (2006). [CrossRef]
  12. G. M. Whitesides, E. Ostuni, S. Takayama, X. Y. Jiang, and D. E. Ingber, Annu. Rev. Biomed. Eng. 3, 335 (2001). [CrossRef]
  13. D. Dendukuri, P. Panda, R. Haghgooie, J. M. Kim, T. A. Hatton, and P. S. Doyle, Macromolecules 41, 8547 (2008). [CrossRef]
  14. D. Dudley, W. M. Duncan, and J. Slaughter, Proc. SPIE 4985, 14 (2003). [CrossRef]
  15. L. J. Hornbeck, Digital Light Processing: A New MEMS-Based Display Technology (Texas Instruments, 1996).
  16. S. Johnson, Stephen Johnson on Digital Photography (O’Reilly Media, 2006).

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