Thesis-PDF - IAP/TU Wien
Thesis-PDF - IAP/TU Wien
Thesis-PDF - IAP/TU Wien
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Second the high photon yield of the photoreceptor and its small size make it<br />
an outstanding detector. It could be used for detecting very low light levels in<br />
environments where space constraints are major issues.<br />
Although the protein sequence has not yet been elucidated and the transduction<br />
pathway remains still enigmatic in part, there is energy conversed from<br />
photons to electrical and then to chemical energy. Converting light into usable<br />
energy is one way for autonomous microdevices to operate. As devices become<br />
smaller and mobile it is crucial that energy is provisioned by the environment and<br />
not from a depletable built-in source. If the photoreceptor of Euglena uses variation<br />
of electrical potentials for its signal transduction as the piezoelectric theory<br />
suggests, it also would be possible to store this energy for later use.<br />
Pellicle Strips - Microtubuli<br />
Self-assembly is a very powerful concept for creating nanostructures. This is one<br />
mechanism the cell uses for the assembly of pellicular strips where individual proteins<br />
bind to binding sites spread on the inner side of the membrane. Functionalization<br />
and coating of surfaces, where the area of effect must be precisely controlled is<br />
also of interest in technical devices. One step further self-assembly of three dimensional<br />
structures as done with pellicular strips starts to emerge also for artificial<br />
materials (e.g. self-assembled batteries, see below).<br />
Microtubuli provide a cell with efficient transportation, information pathways,<br />
gating mechanisms and structural fortification. They exhibit good mechanical<br />
properties and can self-assembly if the tubulin proteins are present. They could<br />
be used in artificial systems that require mechanical flexibility or even active shape<br />
shifting in combination with molecular motors (as pellicular strips being moved<br />
relative to each other). A simple rotory motor could be imagined e.g. as an<br />
assembly of a microtubular ring and an array of kinesin motor proteins that rotate<br />
it (Fig. 4.19).<br />
Vacuole<br />
The vacuole is part of a tuned system to regulate element concentrations in an<br />
aqueous environment. As such it acts as a selective micropump (the output fluid<br />
contains different element concentrations than the reservoir fluid) and its mechanisms<br />
could be useful in a whole range of technical applications. Examples include<br />
the "lab on a chip" for the analysis of different substances (e.g. blood) or regulated<br />
drug release inside the bloodstream.<br />
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