By adding a bit of silver to a thin layer of salmon sperm DNA and sandwiching it all between two electrodes, scientists have created a data storage device that could lead to a cheaper replacement for silicon.
Some resourceful researchers at the National Tsing Hua University in Taiwan and the Karlsruhe Institute of Technology in Germany chose salmon sperm cells for the source of their DNA because they're plentiful and grow fast. That makes them a more economical potential storage device than the high-quality silicon used today.
They created their "write-once-read-many-times" (WORM) memory by combining the above materials and shining a UV light on it. That made the silver atoms bunch into nanoparticles. From Eric Smalley at Wired:
"In the default state the nanoparticles trap electrons, making them electrically resistant. Shine a laser on the film and tiny pathways open between the nanoparticles, making the material electrically conductive. So, shining a laser on a tiny patch of the film writes a bit of data. Send a current through a patch of the film to measure the conductivity, and you can read the data. Low conductivity = 0, high conductivity = 1."
With a charge of 2.6 volts, the device switched to high conductivity and stayed that way indefinitely. That means you should be able go back and retrieve information later, though it's not clear how long the high conductivity state will last.
Other "DNA computers" have been created using E. coli and manmade DNA to perform all sorts of computational tasks. The future of computing, it seems, is very much alive. [Applied Physical Lettersvia Wired via Gizmag]
Image: Flickr/United States Fish and Wildlife Service Pacific