From The Economist, Mar 8th 2014:
The DNA of materials
Angela Belcher is a materials scientist who makes things with viruses. She is now using them to attack cancer
“IT’S getting a little challenging,” says Angela Belcher. “I feel I am having to make choices now, which I never really wanted to.” But there are only so many hours in the day and she already combines multiple academic disciplines into a repertoire of research that spans an ambition to drive an electric car powered by a virus battery to building better touch-screens for digital devices and lately to giving surgeons new tools to detect and potentially treat minute traces of cancer.
There is more, but as eclectic as her work seems, it is united by a single intriguing idea. Evolution is a great problem solver and over millions of years has produced creatures of incredible breadth and complexity that can survive in the changing world around them. So why not copy the way nature innovates, speed it up and use it to help solve some of the problems researchers are presently working on. And that, in essence, is what Dr Belcher and her colleagues at the Massachusetts Institute of Technology (MIT) do. They rapidly evolve genetically engineered organisms to manufacture new materials and devices.
From the oceanIt began in the 1990s with an abalone shell, the sturdy home of a mollusc with a beautifully decorated mother-of-pearl interior. Dr Belcher was researching her PhD at the University of California, Santa Barbara, and was studying how abalones build their shells. The molluscs produce proteins which combine with ions of calcium and carbonate in seawater. This provides the material for them to make two types of crystals, which they assemble into layers to create an immensely strong composite structure.
As she looked out of the window one day while wondering about this, her gaze drifted to a periodic table of elements stuck on the wall. If an abalone has within its DNA the ability to code for the proteins needed to gather the materials to construct a shell, would it be possible to tinker with the DNA sequences in other creatures to gather some of the elements on the periodic table? In particular, Dr Belcher asked herself, could creatures build semiconductors like those used in electronic circuits?
The idea might seem far fetched, but Dr Belcher thought that the reason it had not happened before could be that nature had never been given the opportunity to try. Sea creatures once had soft bodies but started to build shells and bones 500m years ago in a geological period known as the Cambrian. That could have been in response to increasing levels of minerals in the ocean. “It took them 50m years to get good at it,” says Dr Belcher. “Students in a research lab are not that patient.” So the process would need to be speeded up.
The leap from evolutionary biology to semiconductors came naturally to Dr Belcher. She did her bachelor’s degree in creative studies and was allowed to combine different sciences. This highly multidisciplinary approach continued with her three PhD supervisors being experts in molecular biology, chemistry and physics. But it caused a bit of a problem with her first grant proposal in 1999, on becoming a professor at the University of Texas, Austin. The project was to find bacteriophages (a type of virus that infects bacteria, not people) that could be genetically engineered to bind to inorganic materials that they would not normally have an affinity for—in particular, semiconductors. If that was possible, then the viruses might be used as a template to grow and assemble electronic circuits, much like an abalone constructs its shell. It was, said one reviewer of her proposal, an “insane” idea.Dr. Belcher co-founded Cambrios Technologies in 2008. Siluria was spun out of Cambrios and as Wednesday's story relays, just accepted an investment from the most valuable company on earth.
Nevertheless, Dr Belcher stuck with her research and eventually was funded by the US Army. (Though interested in promoting basic science, the army likes to keep a look-out for potential breakthroughs in electronics which might benefit the increasing amount of technological kit it now uses.) In a paper published in 2000 in Nature, Dr Belcher demonstrated that her idea did indeed work. In 2002 she joined MIT and further scientific papers followed in collaboration with a number of her colleagues. Some of those papers explored making the components of a battery using viruses.
The technique begins by genetically modifying the somewhat basic DNA of a bacteriophage. This can be done to produce small but multiple changes in a billion or so viruses. All these variants, huge in number but individually tiny enough to be contained in a droplet of liquid, are then exposed to the material which the researchers are interested in manufacturing. Any viruses that show an affinity towards the material by attaching to it are gathered up. There may be only one or two in a billion, but when these candidates are used to infect a bacteria, millions of copies with identical DNA are made. The process can then be repeated to refine the characteristics. It is akin to high-speed natural selection. With further genetic modification and by changing the growth conditions, the selected viruses are used to bind with specific materials and assemble battery components.
Having found viruses happy to attach to nanowires of cobalt oxide, the researchers were able to produce a negative anode, one of the two main functioning parts of a battery. Making a positively charged cathode, the other important bit, was more difficult because for a battery to work well the cathode needs to be highly conductive. Nevertheless, Dr Belcher and her colleagues succeeded in getting some viruses to attach to carbon nanotubes, which are very good at conducting electrons. This resulted in a suitable cathode. It was then possible to assemble virus-made components into a small cell battery capable of lighting up an LED.....MUCH MORE
She is a director of Siluria.
She is also on two different MIT faculties:
The Department of Materials Science and Engineering
The Department of Biological Engineering
Her latest paper, published in late July, demonstrated a method for recycling old car batteries into solar cells.
I hate her.
Did I mention she does cancer research?
As I said, scary-smart.