Quantum computing and DNA origami

Theme for the day: science fact is even better than science fiction. Jonathan Hodgkin has a rather enchanting TLS piece about two recent books on biocomputing and twenty-first-century technology:

For solving some computational problems, it is possible to encode the problem in a complex soup of many different DNA molecules. Complementary DNA molecules are able to find and pair with one another, so with the right tricks a unique solution can be extracted from the soup. Gradually, more and more complicated problems are being attacked by this kind of approach, which is radically different from conventional computing. The second strand is the use of DNA in micro-fabrication, to construct minute structures by exploiting the ability of DNA to fold up in specific patterns dictated by base pairing. This process, sometimes called DNA origami, is tremendous fun, and has led to recent advances such as the synthesis of bits of DNA that spontaneously fold up into two-dimensional shapes like smiley faces, or maps of America. The smiley faces are a few millionths of an inch across, so they can only be seen with an atomic-force microscope, but they can be made by the billion, because it is so easy to replicate DNA. As a result, the scientists involved joked that they had been responsible for “the most concentrated happiness ever created”. Other scientists have gone on to make tiny motors attached to a DNA scaffold, or stable three-dimensional objects made of DNA. There seems to be no end in sight for ingenious creative developments in this area.