Biomedical Engineering Reference
In-Depth Information
a
c
10 µm
b
10 µm
d
10 µm
10 µm
FIGURE 1.23
Micromolding.in.capillaries..SEMs.of.polyurethane.microstructures.on.Si/SiO
2
.formed.
using.a.commercially.available,.UV-curable.polyurethane.prepolymer.used.for.optical.parts..(a) Lines.
on.Si/SiO
2
..(b).Complex.pattern.containing.interconnected.features..(c).Quasi-3-D.pattern.contain-
ing.multiple.thicknesses.molded.in.a.single.step..(d).Free-standing.ilm.formed.by.MIMIC.followed.
by.dissolution.of.the.support.in.HF..(From.Kim,.E.,.Y..Xia,.and.G.M..Whitesides,.“Micromolding.in.
capillaries:. Applications. in. materials. science,”.
J. Am. Chem. Soc
.,. 118,. 5722,. 1996.. Reprinted.
with.permission.of.the.American.Chemical.Society.)
(a)
(b)
100 µm
100 µm
FIGURE 1.24
Microluidically.patterned.polyurethane.3-D.structures..(From.Folch,.A.,.S..Mezzour,.
M.. During,. M.. Toner,. and. R.. Muller,. “Stacks. of. microfabricated. structures. as. scaffolds. for. cell.
culture.and.tissue.engineering,”.
Biomed. Microdevices
,.2,.207,.2000..Figure.contributed.by.the.
author.)
2. he material to be patterned does not need to be dried. hus, the concerns about pro-
tein denaturation that apply to microstamping do not apply to microluidic patterning.
3. Replica-molding the microchannels from the master is straightforward, nonhazard-
ous, and inexpensive (in terms of both materials and human labor).
4. he molding procedure leaves the master intact; thus, the most expensive part of
the process, photolithography—or any other method used to pattern the master—is
needed only once.
5. he patterning procedure usually does not damage either the sample or the channels
(thus, the channels can be reused).
