Thesis-PDF - IAP/TU Wien

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