How fast and powerful can computers become? Will it be possible someday to create artificial brains that have intellectual capabilities comparable to those of human beings? The answers to these questions depend to a very great extent on a single factor: how small and dense we can make computer circuits. Very recently, scientists have achieved revolutionary advances that may very well radically change the future of computing.

There are significant advantages to using biological molecules in a new computational paradigm, since nature has solved similar problems to those encountered...