Molecular spiders can cut grass, fight one another, and save lives?

If you've read Engadget for any period of time, you know that we love robots. What do we love more than ordinary robots? Spider robots. But what do we love even more than spider robots? There's only one obvious answer: molecular robot-like spiders. The BBC has just reported on such research from Columbia University by Dr. Milan Stojanovic, a professor of biochemistry. Dr. Stojanovic and his team have built what they call a "molecular spider" that has four legs, each of which are made up of 10nm strands of DNA. The spider, once let loose in a solution of molecular-sized grass, acts as a miniature lawnmower when it releases an enzyme catalyst that cuts the tiny blades. But Dr. Stojanovic isn't stopping there -- he says that he plans to build a microscopic arena for dueling spiders to go at it: "We could have a simple predator-prey system in which one of them would try to cleave the legs of the other." However, the Beeb had to go and get a practical answer from him, explaining that "insulin could be steadily released from the surface of a tablet: if the spiders were sensitive to blood glucose, they could be automatically activated or halted according to the diabetic patient's immediate needs." That's useful, but BOR-ING! Dr. Stojanovic, let us know when we can start betting on molecular spider gladiator fights, ok?

[Thanks, Chris W., illustration courtesy of the BBC]