Biomedical Engineering Reference
In-Depth Information
depending.on.the.factors.such.as.solution.concentration..As.a.result,.the.printed.thin-ilm.
structures.could.either.be.of.the.same.dimensions.as.the.stamp.relief.features.or.be.smaller.
than.the.features.
11.3.2.11 Nanoparticles
Nanoparticles. are. nanometer-sized. structures. and. have. a. wide. range. of. applications..
Santhanam.and.Andres.(2004).developed.a.novel.method.for.printing.nanoparticles..In.
their.method,.a.dense.monolayer.of.nanoparticles.was.irst.self-assembled.on.an.air-water.
interface,.then.transferred.on.a.PDMS.stamp,.and.inally.printed.on.to.a.substrate.with.
patterns..Alternatively,.Kim.et.al..(2008a).directly.deposited.a.dense.monolayer.of.quan-
tum.dots.on.a.PDMS.stamp.by.spin.casting.and.printed.the.quantum.dots..Nanoparticles.
have.also.been.printed.with.single-particle.precision.by.loading.individual.nanoparticles.
into.nanometer-sized.recessive.features.of.a.stamp.through.a.dewetting.process.(Kraus.
et.al..2007).
11.3.2.12 Carbon Nanotubes
Carbon. nanotubes. possess. a. unique. set. of. characteristics. and. tremendous. potential. for.
numerous. applications.. Meitl. et. al.. (2004). patterned. single-walled. carbon. nanotubes.
(SWCNT).using.μCP..In.their.method,.an.aqueous.solution.of.surfactant.stabilized.SWCNT.
was. applied. to. a. rotating. PDMS. stamp. with. an. organic. solvent,. such. as. methanol,. for.
removing.the.surfactant..As.a.result,.a.thin.ilm.of.SWCNT.formed.on.the.stamp.and.was.
later.printed.on.a.substrate..Thin-ilm.transistors.were.built.on.the.printed.SWCNT.pat-
terns..Fuchsberger.et.al..(2011).developed.a.different.method.to.produce.multiwalled.car-
bon.nanotube.(MWCNT).functionalized.microelectrode.arrays.based.on.μCP..They.irst.
used.a.iltration.method.to.generate.a.thin.ilm.of.MWCNT,.which.was.then.transferred.
on.to.a.PDMS.stamp.by.intimate.contact..The.MWCNT.on.the.stamp.was.inally.printed.
on.the.microelectrodes.
11.3.2.13 Metal Films
Micro/nano-patterned. metal. thin. ilms. are. essential. components. of. most. electronic.
devices.. Zaumseil. et. al.. (2003). developed. a. μCP. method. called. nanotransfer. printing. to.
print.metal.ilms..In.this.method,.a.thin.ilm.of.metal.was.deposited.on.a.stamp.with.relief.
structures. by. vapor. evaporation. and. the. ilm. was. printed. on. an. adhesive. substrate.. In.
addition.to.simple.2D.structures,.this.method.allows.fabrication.of.three-dimensional.(3D).
multilayer.stacks.by.multiple.printings.
11.3.2.14 Live Cells
Benign.conditions.are.required.to.maintain.live.cells..The.conditions.are.largely.incompat-
ible.with.conventional.microfabrication.techniques..μCP.is.unique.for.its.ability.to.print.
live.cells..In.one.method,.Xu.et.al..printed.live.bacteria.by.culturing.a.layer.of.bacteria.on.
a. lat. agarose. gel,. inking. a. PDMS. stamp. with. relief. structures. by. placing. the. stamp. on.
the.bacterial.layer,.and.printing.the.bacteria.on.a.second.piece.of.agarose.gel.substrate..In.
another.method,.Stevens.et.al..(2005).printed.mammalian.cells.also.using.agarose.hydro-
gel.stamps.