Is organic computing finally here?

Various concepts of a wireless molecular circuit. In panel a) you see the DDQ molecule that the researchers used. The next panels show the molecule in its various states and configured as organic circuits. Image courtesy research paper: A massively parallel computing on an organic molecular layer, A. Bandyopadhyay, R. Pati, S. Sahu, F. Peper, D. Fujita, Nature Physics 6, 369 (2010).

Japanese scientists have made organic molecules perform parallel computations like neurons in the human brain. They created this promising new approach with a ring-like molecule called 2,3-dichloro-5,6-dicyano-p-benzoquinone, or DDQ.

Today, computer chips can process data at 10 trillion (10¹³) bits per second. But, even though neurons in the human brain fire at a rate of 100 times per second, the brain still outperforms the best computers at various tasks. The main reason being that calculations done by computer chips happen in isolated pipelines one at a time. 

Now, Anirban Bandyopadhyay, a scientist from the National Institute for Materials Science in Tsukuba, Japan, and his colleagues have exploited the unusual properties of the molecule DDQ by calculating real scientific problems. “Generalization of this principle would change the existing concept of static circuit-based electronics and open up a new vista of emergent computing,” said the researchers.

The circular DDQ molecule can exist in four different conducting states, depending on the location of ‘trapped’ electrons around its ring. The researchers switched the molecule from one state to the other by ‘hitting’ it with varying voltages using the tip of a scanning tunneling microscope. In essence the initial state of the molecule was programmed by the scanning tunneling microscope. The molecules states could even be changed by placing it in an electric field.

When two of the molecules were placed next to each other, they could be connected, and up to six DDQ molecules were connected simultaneously. The Japanese researchers then laid down 300 DDQ molecules as a single layer on a gold substrate, making this into a massive parallel computing infrastructure with only a single layer of organic molecules to calculate the way heat diffuses in a conducting medium and the way cancer spreads though tissue. Their research paper was published in arXiv.org.