Biomedical Engineering Reference
In-Depth Information
200 µm
1 mm
500 µm
300 µm
FIGURE 13.10
SEM.of.ink.structures.on.PO.ilms..Microstructures.can.be.generated.on.PO.ilms.simply.by.printing.(single.
print).onto.the.polymer.sheets..These.microstructures.can.be.for.the.fabrication.of.microluidic.devices,.negat-
ing.the.need.for.standard.photolithography.
ilms.were.laminated.onto.nonshrinkable.polyester.backing.using.a.high-tack,.low-bond.
strength.latex.adhesive..This.lamination.process.allowed.for.the.PO.ilm.to.slide.along.the.
backing. and. prevented. contortion. of. the. ilm.. In. addition,. slowly. applying. heat,. irst. at.
115°C,.then.at.135°C,.and.inally.at.155°C,.prevented.the.delimitation.of.the.PO.sheet..From.
this.process,.we.observe.that.the.protein.array.exhibited.a.signiicant.reduction.in.size.as.
well.as.a.dramatic.increase.in.luorescence.(Figure 13.11).
The. ability. to. generate. self-assembled. micro-. and. nanostructures. plays. an. important.
role.in.the.integration.of.biochips.and.POC.diagnostics..An.example.of.such.an.applica-
tion.is.the.regulation.of.a.cellular.microenvironment;.speciically,.substrate.modiication.
has.been.shown.capable.of.eliciting.speciic.cellular.responses.such.as.cell.alignment.
72,73
.
Further,.as.a.potential.application.of.such.structures.in.the.µTAS,.it.has.been.shown.that.
by. altering. these. structures,. it. is. possible. to. tune. the. surface. plasmon. effect,. leading. to.
the.enhancement.of.luorescent.signals.
31
.Thus,.by.utilizing.the.mismatch.in.the.metallic.
ilm.and.the.PO,.it.is.possible.to.generate.metallic.nanostructures.that.are.smaller.than.the.
previous.reported.wrinkles.utilizing.PS.sheets
31
.(Figure 13.12).
With.the.use.of.commercially.available.PO.thermoplastic,.it.was.demonstrated.that.the.
patterning.of.microstructures.can.be.achieved,.negating.the.use.of.standard.hot.emboss-
ing.and.photolithographic.methods..These.POs.exhibited.a.95%.reduction.in.feature.size.
upon.the.induction.of.heat.and.can.be.utilized.for.microluidic.applications..Further,.by.
applying.standard.protein.patterning.and.self-assembled.nanostructures,.PO.ilms.can.be.
used. to. generate. high-density. microarrays,. which. can. be. applied. to. biochip. designs. for.
point.of.care.diagnostics.
