But indeed, mad (perhaps) scientists of the world are devising ways to do just that. Researchers at Penn State University are looking into developing tiny, spidery machines that swim around in people's blood vessels. It sounds awfully evil but their intentions seem pure; they're trying to find new ways to deliver medicine to specific locations in the body.
Modern medicine is pretty incredible stuff, but we haven't quite got the hang of localizing it internally yet. Chemotherapy can help kill cancer cells in many patients, but it also has the unfortunate side effects of killing lots of other healthy cells that doctors would ideally like to keep alive. Most medicines act in broad strokes, applied equally to large parts of the body instead of just the sick ones. Loading up tiny honing missiles with medicine and sending them to infected areas could be one way of improving the effectiveness of medicine.
The little dudes could help patch you up from the inside, too. Wielding a kind of medical glue, they could pass by tears in blood vessel walls and close them back up. With the right backup of certain enzymes and other micromachines, they could even wear down plaque from the inside of your blood vessels, unclogging arteries and keeping that blood pressure down. They might even be able to recognize and attack tumors at some point.
Scientists have been at work on medical micromachines for a while now, but these little spiders are the first to use a micromotor based on polymerisation. The spiders would actually look more like half gold, half silver Christmas balls. One side is literally the element gold and the other is made of silica. A catalyst builds chains of small molecules--the spider "legs", I'm assuming--which ultimately spin and propel the nanosphere forward. So far they've only been able to scoot around tanks of solvent, which are slightly less complicated than the human body. They don't even react to chemicals naturally found in humans yet. But it's certainly a start, and an exciting one at that. I look forward to the day where medical issues can be solved by sending a fleet of tiny, robotic warriors into the body. Not only could the microbots reduce a whole heap of side effects for people suffering from conditions that are now only treatable with full-body wallops, but the whole concept also reminds me of that one Placebo video from the end of the '90s. I hope Penn State sees some forward motion from this project--for the sake of medicine and for the sake of awesome.