Biomedical Engineering Reference
In-Depth Information
device in the form of arrays of reservoirs that facilitate dispensing of luids in parallel
(e.g., with a multipipettor, if the array matches the spacing of a 96-well plate).
U
UEA:
See
Utah electrode array.
ultrasound-based micropump:
Microfabricated pump that exploits the use of ultrasound to
propel luids.
Utah electrode array:
A 10 × 10 array of microfabricated, individually addressable, high-aspect-
ratio silicon needle electrodes (1.5 mm tall, 400 μm spacing) for intracortical implanta-
tion, developed at the University of Utah's Center for Neural Interfaces.
V
van der Waals force (between two bodies):
he sum of all dipole-dipole interactions (attractive
and repulsive) between the two given bodies under consideration, for example, the van
der Waals force between two molecules or the van der Waals force between a molecule
and a surface.
W
weir:
In hydraulics, a type of dam consisting of a barrier that allows water to overlow over the
barrier. In microluidics, the weir is usually built inverted (i.e., hanging from a roof) so
as to act as a particle trap.
Western blot:
Technique used for the separation of speciic proteins in a given extract or homog-
enate of tissue or cells. Separation is performed by gel electrophoresis according to the
length of the polypeptide chain of the protein (if the protein has been denatured) or
according to the 3-D structure of the protein (if the protein is in its native conforma-
tion). Once separated, the proteins are transferred to a PVDF or nitrocellulose mem-
brane in which they are detected by antibodies to the protein of interest.
wet etch:
In microfabrication processing, an etch that uses liquid chemistry (as opposed to an
etch that uses gaseous chemistry;
see
dry etch).
X
Xenopus:
Genus that includes 19 species of sub-Saharan aquatic frogs, of which
Xenopus laevis
is
a highly used model organism in developmental biology research.
Xenopus
oocytes are
convenient protein expression systems and are commonly used in ion channel research.
Y
YIGSR:
Sequence of ive amino acids (Y, tyrosine; I, isoleucine; G, glycine; S, serine; R, arginine)
that is present in laminin; when integrin receptors on the membranes of adherent cells
recognize the YIGSR sequence, the cells attach and spread on the surface that is cov-
ered with YIGSR.
Young equation:
Equation derived by homas Young (1773-1829) that relates the surface ten-
sions between the three phases surrounding a droplet on a surface (gas, liquid, and
