Crests Low-Dimensional Chemistry

Towards biologically inspired design

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Our science

The metal-oxide-semiconductor field-effect transistor (MOSFET) is one of the most important engineering discoveries of the 20th century. There are billions in every computer, but they aren't just found in laptops and desktops - they're in phones, iPads, credit cards, central heating control systems, burglar alarms...everywhere! In common with other engineering devices, MOSFETs are predictable: they behave deterministically, which means that a particular input always produces the same output; they are built from hard, precisely engineered inorganic (ie non-living) components; and the respond to simple signals (series of 1s and 0s).

Nothing could be more unlike the kinds of systems that carry out photosynthesis in bacteria and plants. Biological systems are composed of molecules that are in constant random motion ("Brownian motion"), even when they are embedded into the surface of a cell, a thin film that is only two molecules thick and which is held together by only the weakest forces. Biological systems don't work by binary logic - they follow complex signals, for example gradients of the concentration of another molecules or ion. And finally, they do not behave in the predictable way that transistors do - biological systems are "stochastic" which means that repeating the same experiment a large number of times will produce a spread of results because of the variability that is intrinsic in biology.

And yet photosynthetic systems capture sunlight with an astonishing efficiency. While the best silicon-based solar cells capture about 12% of the sunlight that falls on them, the figure is much closer to 100% for photosynthetic bacteria. So while biological systems aren't built the way an engineer would design them, they work really well. Which raises an interesting question: if biological systems work so well, why don't we use the same kind of "design principles" to build engineered devices, like solar cells? This question is the motivation for our project. Our goal is to dismantle the photosynthetic pathway of a bacterium, and then try to reassemble it on a chip. In the process we hope to learn how the biological system uses very different mechanisms from those used by engineers to achieve such remarkable efficiency.

What do we do?

Studying photosynthesis

Lipid bilayers

Building molecular nanostructures

Seeing molecules