266 Color Inserts
ϭϬ ϭϱ ϮϬ Ϯϱ ϯϬ
Figure 6.3 Viscosity as a function of temperature for high concentrations of sodium
phosphate in a 15 wt% Pluronic F127 solution in water from cone and plate viscometry
at controlled shear stress (0.6 Pa s).
Figure 6.5 A schematic illustration of the principle of an active valve using a thermally
responsive ﬂuid in a microﬂuidic network. (a) Fluid from one channel is d iverted into two
channels at a channel bifurcation; (b) activating an integrated heater leads to localized gel
formation in the corresponding microchannel, which subsequently blocks this channel to
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Color Inserts 267
Figure 6.7 A schematic cross-section of the microﬂuidic device shown in Fig. 6.6. The left-
hand side shows the cross-section across a heater in the channel, while the right-hand side
shows a cross-section further away from the channel, through an aluminum lead.
Figure 6.9 The ﬂow ﬁeld at the channel bifurcation shown in Fig. 6.6. The velocities
were evaluated from images of the seed particles as in Fig. 6.8 using PIV; (a) before valve
actuation, (b) 33 ms later; blue: below 40 μm/s, green: 40–80 μm/s, yellow: 80–120 μm/s,
orange: 120–160 μm/s.
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268 Color Inserts
Figure 6.10 Experimental setup for the demonstration of passive ﬂow control using ther-
mally responsive Pluronic solutions at constant ﬂow rate in microchannels.
Figure 6.14 Top view of a microﬂuidic device. Pluronic solution and saline solution are
introduced in a 10 μm high microchannel at T
C. Gel formation occurs in the center
of the channel. The Pluronic stream is seeded with ﬂuorescent particles.
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Color Inserts 269
Figure 6.16 Thickness of the gel wall along the channel for different experimental condi-
Figure 7.5 BioMEMS multi-array prototype implanted subcutaneously in a rodent model.
The local environment had encapsulated the device in an attempt to isolate it from the body
(28 days post-implantation).
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270 Color Inserts
Figure 7.8 BioMEMS micro-array prototype. The inner-reservoir surface area is larger than
it appears from a top view (A). The activation of the entire multi-array reservoir system
leads to dissolution of the reservoir sealing membrane, release of the drug, and the onset of
a “new” inﬂammatory response initiated by the exposed surface of the inner reservoir (B).
Figure 8.1 Amount of protein adsorption on a given oligoether SAM on gold normalized
to the amount of protein adsorbed on a monolayer of hexa-decanethiol on gold (100%)
versus advancing aqueous contact angle of the SAM. Symbols: red
OH; blue ,EG
OMe; light blue •,
OMe; red ×,EG
OMe; blue ,TRI
OMe; red ×,PRO
OPr; blue •,
OBu. Images adapted from Ref. 54.
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