Biomedical Engineering Reference
In-Depth Information
rod or bead) is moving in the vicinity of an electric current capturing de-
vice (e.g. a metallic wire loop). Many elements of the devices proposed by
Montemagno's team prompt to this application (but not exclusively) with the
rotary motor based devices already being organized in micro- and nanoar-
ray formats (Fig. 6.13). An engineering study [73] tested the hypothesis of
obtaining a reasonable electric current from an array of nano-electric genera-
tors, i.e. beads moved by actin-myosin system in microfabricated structures.
It was found that, in an ideal situation, although the generated electric field is
approximately a few tens of pV per bead, a purposefully designed array would
amplify this to several nV - enough for micro-level local needs, e.g. powering
electronic circuits.
Anumberof
devices performing mechanical functions
have been recently
proposed by a group at University of Washington. A light-powered nano-
assembly line uses molecular shuttles, which exploit UV-induced release of
caged ATP combined with enzymatic ATP degradation, and which carry car-
gos along engineered paths [74]. Also a forcemeter capable of measuring the
strength of biological receptor/ligand pairs i.e. pN forces, has been demon-
strated [75]. The device is assembled from nanoscale building blocks, using
a cantilevered MT as a beam of known stiffness, loaded by a second MT
transported by kinesin.
Fig. 6.16.
Confinement of the movement of actin filaments in channels (left) and
color-coded trajectories of actin filaments (right: red and purple - start and end of
sequence). (Adapted from [67]. Copyright 2002 Kluwer Academic Publishers)
