Best Inventions of 2001

Inventor: Ian Kelly

They are every gardener's nightmare: big, slimy slugs that eat holes in lettuce leaves and gouge craters in tomatoes. Now Ian Kelly, a computer scientist at the California Institute of Technology, has developed a robotic slug catcher that not only identifies and eliminates slugs but could eventually power itself with its victims' bodies. Here's how the Slugbot works: a lawn mower­ size machine with a long arm shines red light on the ground to identify a shiny, sluglike object, then analyzes its shape. When it finds a slug, it picks it up and drops it in a hopper. Bacteria inside the robot eat the slimy critters—a process that releases electrons that can be captured and, in theory, keep the bot's batteries perpetually charged. Kelly says he has perfected the slug-identification-and-retrieval system but estimates that it will be several years before the slugbot is ready for market. Biggest hurdle: getting the robot to convert those captured mollusks into usable energy. While the concept of microbial fuel cells has worked in laboratory tests, applying it to slugs turns out to be a sticky proposition.

Availability: About 2004
To Learn More: www.micro.caltech.edu