Probably the most masterful and mysterious act of chemical computation is when a single cell uses its DNA to divide, multiply, and specialize to produce a fully developed organism. In research reported this week in Nature, computer scientists took a small but important step toward harnessing the potential of chemical computation by constructing the first broadly programmable DNA computer.
The system executes a wide variety of 6-bit programs using a set of instructions written in DNA. The researchers used it to perform 21 test programs, though the system is capable of many more. Previous DNA computer schemes were essentially bespoke systems, only capable of solving the single problem they were designed for.
The new system, which is made of just DNA and salt water, is unlikely to find a technological application itself. But it is a step toward developing self-assembling programmable matter, where chemical software automatically directs the construction of materials with complex, programmable nanometer-scale features. Its creators were “trying to understand how to embed computational behaviors within chemistry in order control what chemistry does,” explains Erik Winfree, the professor of computer science and bioengineering who led the research, which was mostly conducted at Caltech.