Biomedical Engineering Reference
In-Depth Information
Oblique view
Cross section
Paper
Photoresist
a
Paper
b
1. Impregnate with
photoresist
5 mm
c
2. Pre-bake
3. Align under a mask
Mask
FITC-BSA
4. Expose to UV light
5. Post-bake
d
e
6. Develop
FIGURE 3.16
Paper.microluidics..(a).Schematic.of.the.method.for.patterning.paper.with.hydropho-
bic.photoresist..A.10.μM.solution.of.FITC-BSA.dissolved.in.40.mM.phosphate.buffer.(pH.7.4).was.
wicked.into.a.paper-based.device.and.imaged.under.UV.light.(254.nm)..The.FITC-BSA.distributes.
evenly.throughout.the.channels.and.test.zones..(b-e).Images.of.a.device.before.(b).and.after.(c-e).
wicking.1.μL.(c),.2.μL.(d).and.5.μL.(e).of.the.FITC-BSA.solution..(From.Andres.W..Martinez,.Scott.T..
Phillips,.Emanuel.Carrilho,.Samuel.W..Thomas.III,.Hayat.Sindi,.and.George.M..Whitesides,.“Simple.
telemedicine.for.developing.regions:.Camera.phones.and.paper-based.microluidic.devices.for.real-
time,. off-site. diagnosis,”.
Anal. Chem.
80,
3699-3707,. 2008.. Reprinted. with. permission. of. the.
American.Chemical.Society..Figure.contributed.by.George.Whitesides.)
for a renewed vision in which any heterogeneous-low microluidic assay will be implementable in
paper. Furthermore, unlike traditional microluidic channels, in the paper format, the microchan-
nel is (a) readily accessible for sample introduction (so it should be ideal for analyzing “forensic-
style” samples—like a “microluidic swap”—that are usually obtained from soil, skin, sweat, semen,
vaginal luid, or other secretory glands in minute quantities); and (b) it de facto incorporates a ilter,
which should be invaluable for iltering cell debris, dirt, and other impurities in blood samples.
FIGURE 3.17
Laminar.low.patterns.created.in.laser-cut.paper.microchannels..(Figure.contributed.
by.the.author.)
