If you thought that Japan was merely the master of miniaturization, tentacles, and creepy robots, think again: A group of Japanese scientists have built a massively-parallel, brain-like computer out of an organic molecule called DDQ. This computer, which is built from 300 DDQ “neurons,” has successfully calculated how heat diffuses through a medium, and the mutation of normal cells into cancer cells. From the very start of the research paper, the scientists point out a phenomenon that all computer geeks are aware of: for the most part, computer processors are single-threaded, sequential-logic machines. You can throw more cores at the problem, or thousands of CPUs (as in supercomputers), or scale to thousands of megahertz, but silicon, transistor-transistor, clock-driven computers are essentially sequential. Animal brains, on the other hand, are almost the complete opposite of modern CPUs: neurons can only fire around 100 times per second, but in a human brain there could be hundreds of millions of neurons all firing at the same time, and each neuron can have a 1,000 synapses to other neurons. It is this scaling, massively-parallel computation that the scientists have recreated using molecules. The work of Anirban Bandyopadhyay and his team from the National Institute for Materials Science in Tsukuba, Japan, revolves around a molecule called 2,3-dichloro-5,6-dicyano-p-benzoquinone, or DDQ for short. DDQ is a ring molecule that can connect with up to six neighboring DDQ molecules. Most importantly, each DDQ molecule can be programmed into four different states, each conducting electricity differently. 300 DDQ molecules are placed on a gold substrate, and their conductive states and connections to other molecules are programmed using a scanning tunneling microscope. The end result is a cellular automaton of 300 neuron-like molecules that can perform calculations in a massively parallel way. For now, it seems like DDQ has only been used to perform pre-programmed calculations — and while that’s useful, conventional computers are unlikely to be usurped any time soon. It is another characteristic of DDQ “brains” that is most intriguing: When a DDQ molecule changes state, the change ripples down through the molecules that it’s connected to, destroying old bonds and creating new circuits as it goes — much like a neuron making new synapse connections. This could eventually lead to emergent computing, where the DDQ brain can react to external stimuli and evolve over time.
Sunday, October 30, 2011
Scientists Create Brain-Like, Massively Parallel Computer from Molecules
