Biomedical Engineering Reference
In-Depth Information
and complicated geometries in which traditional fabrication technologies cannot reach, such
as in the assembly of components on curvilinear surfaces (e.g., an electronic contact lens, see
Section 8.2.6), in tissue engineering, in microrobotics, etc.
1.10 Summary
Photolithography, the miniaturization of components with light as used routinely for the fab-
rication of microelectronics, constitutes the starting point for miniaturization in BioMEMS.
Because of its materials and costs constraints, however, most of the current work on BioMEMS
relies on sot lithography, based on the patterning of materials with the elastomer PDMS, a
material that has many useful properties for biopatterning and for device fabrication. he irst
step of sot lithography is the fabrication of a master mold using photolithography. PDMS rep-
licas of this mold can be used to make stamps and microluidic devices, which are then used to
selectively deposit the material of interest in selected locations. Approaches based on hydrogels
(e.g., agarose), biocompatible photoresists, and self-assembly are emerging as powerful alterna-
tives or complements to PDMS for biopatterning.
Further Reading
Abgrall, P., Conedera, V., Camon, H., Gue, A.M., and Nguyen, N.T. “SU-8 as a structural material for labs-
on-chips and microelectromechanical systems,”
Electrophoresis
28
, 4539-4551 (2007).
Ariga, K.
,
Hill, J.P., Lee, M.V., Vinu, A., Charvet, R., and Acharya, S. “Challenges and breakthroughs in recent
research on self-assembly,”
Science and Technology of Advanced Materials
9
, 1-96 (2008).
Banta, S., Wheeldon, I.R., and Blenner, M. “Protein engineering in the development of functional hydrogels,”
Annual Review of Biomedical Engineering
12
, 167-186 (2010).
Bishop, K.J.M., Wilmer, C.E., Soh, S., and Grzybowski, B.A. “Nanoscale forces and their uses in self-assem-
bly,”
Small
5
, 1600-1630 (2009).
del Campo, A., and Greiner, C. “SU-8: a photoresist for high-aspect-ratio and 3D submicron lithography,”
Journal of Micromechanics and Microengineering
17
, R81-R95 (2007).
Madou, M.
Fundamentals of Microfabrication
, 752 pp. CRC Press (2002).
Maruo, S., and Fourkas, J.T. “Recent progress in multiphoton microfabrication,”
Laser & Photonics Reviews
2
, 100-111 (2008).
Qin, D., Xia, Y., and Whitesides, G.M. “Sot lithography for micro- and nanoscale patterning,”
Nature
Protocols
5
, 491-502 (2010).
Wang, W., and Soper, S.A. (editors),
Bio-MEMS: Technologies and Applications
, 477 pp. CRC Press (2007).
Weibel, D.B., DiLuzio, W.R., and Whitesides, G.M. “Microfabrication meets microbiology,”
Nature Reviews
Microbiology
5
, 209-218 (2007).
Wikipedia article on etching, “Etching (microfabrication),” see http://en.wikipedia.org/wiki/Etching_
(microfabrication).
Xia, Y., and Whitesides, G. “Sot lithography,”
Angewandte Chemie (Int. Ed.)
37
, 550-575 (1998).
