Bacteriorhodopsin (BR) is a light-sensitive biomolecule found in the purple
membrane of the archaean Halobacterium salinarium. Due to its exceptional
durability, BR has been proposed for a variety of technical applications. At
LUT, the main research focus has been on dry bacteriorhodopsin thick films.
The electrical and optical properties of the films have been studied and they
have been used to construct photosensors and a color-sensitive camera. The
origin and mechanism of the photovoltage generation in these sensors is
not fully understood. In order to study the origins of the measured
photovoltage, we have developed both a simulation environment, and in
collaboration with researchers on electronics, better measurement electronics
for the research. The simulation environment provides a tool to test different
models for the BR photocycle and the electronics. The possibility to design a
novel imaging sensor incorporating different types of BR in a layered
structure is also studied. This type of sensor provides higher spatial
resolution, and due to the active nature of the biomaterial, it is possible to
change the properties of the sensor during the image capture. This is expected
to improve the controllability and increase the signal-to-noise ratio of the
sensor in different applications.
