Top 5 Green Robots

If you happen to view the "Matrix" film trilogy as gospel, then you know that machines will eventually overthrow their human masters and enslave humans in a massive electronic generator. Kung fu and explosions ensue.

If you look around, you'll probably note that modern robots aren't up to the task. Seriously, if a Roomba can't outsmart a cat, then what chance do the machines have against humans?

Well, the University of the West of England's Bristol Robotics Laboratory studied the idea of a robot predator in the late 1990s. The engineers developed a prototype for a robot with a prime directive: catch garden slugs and turn them into fuel. Obviously, the mechanical and programming demands of such a venture deserve credit, but it's the focus on turning a garden pest into energy that really makes the SlugBot a green automaton.

Designs called for the bot to catch 10 slugs a minute during the night, store them in a container and then return to its base to recharge and dump the disgusting mollusks into a fermentation chamber. There, bacteria would convert the creatures into biogas, which would in turn load a fuel cell for the SlugBot's next field trip.

The slugs of the world are safe for now, though. The team behind SlugBot has moved on to the creation of all-new robo predators, including the self-powered, fly-eating EcoBot II, which attracts its prey by emitting an odor similar to that of human excrement. The team also is working on EcoBot III and has explored the idea of creating a plankton-munching, self-powered robot to live in the ocean.

On one episode of TV's "Futurama," famed robot Bender "Bending" Rodriguez noticed a small robot cleaning up some trash. Outraged, the feisty automaton exclaimed, "And look who's cleaning up the crap! A human child? I wish!"

Bender would likely express even more outrage if he were to travel to modern day Germany, where electric mole or "pig" robots are, quite literally, cleaning up the crap. Produced by Thermo-System, the wheeled robots truck through human waste, using harnessed solar energy to help dry an estimated 60 millions tons (54 million metric tons) of sewage a year in Germany alone [source: Thomas]. As the robots truck through the sludge, they also turn it, aerating the ravenous microbes.

Robot civil rights issues aside, the electric moles keep operating costs and carbon emissions low for sewage treatment plants.

Humans love a good lake. Aside from safeguarding irrigation water, large bodies of water are great for boating, swimming and any number of associated summer pastimes. We're also quite fond of creating our own lakes when nature proves stingy. Just dam the river downstream and -- ta-da -- what was once a valley is now a man-made reservoir ripe for your weekend plans.

Sounds great, right? But creating a man-made lake tends to leave a lot of valuable lumber rooted to the bottom of the lake. In fact, there's an estimated 300 million salvageable submerged trees out there with an estimated value of $50 billion [source: Gordon]. Why cut down oxygen-purifying, carbon-collecting trees on the surface when we could be harvesting sunken treasure?

This is where Triton Logging's Sawfish enters the picture. The 7,000-pound (3,175-kilogram) remote-control submarine dives down, attaches airbags to the tree trunk and then gets to sawing. Triton currently harvests Douglas fir, Western white pine, lodgepole pine and hemlock year round in British Columbia. Not only is this robot green, it's actively raking in the dough.

There are plenty of robotic submarines out there, from the Sawfish underwater lumberjack to such deep-diving explorers as the deep-sea Zeus II. Although these machines make it possible for humans to explore such fishy realms from a safe distance, they lack the finesse of good old Mother Nature.

On one hand, you have creatures such as the octopus, which can ghost across fragile coral landscapes and squeeze itself through the tightest of spaces. And then, in humanity's corner, you have enormous bulky subs with small, cumbersome arms.

Researchers from Greece, Italy, Israel, Switzerland, Turkey and the United Kingdom have proposed a compromise: soft, robotic tentacles. Cleverly dubbed the roboctopus by the likes of New Scientist magazine, the resulting underwater robot would be able to dance its way into delicate environments without disrupting or damaging the surroundings. While there's nothing inherently green about biomimicry (you could, in theory, build a robot crab programmed to eat hybrid cars), the roboctopus would allow scientists to better hunt for signs of climate change in narrow ocean floor cracks and amid fragile coral.

Every soft tentacle would contain four cords, each containing electroactive polymers that contract when hit with an electric field, causing the tentacle to flex this way or that. Developers are still working up to producing an actual prototype, but it could represent the ultimate in less invasive seafloor exploration.

Sure, robot octopi may one day comb the ocean floor for signs of global warming, but then what? What robots will save us if we need to turn down the planetary thermostat a few degrees to avoid environmental catastrophe? Well, lucky for us, professors John Latham and Stephen Salter have thought up a solution. How does a fleet of about a thousand robotic, cloud seeding ships sound?

The idea behind this geoengineering (or planet hacking) scheme is that by reflecting a mere 3 percent more solar radiation, we could counter a great deal of the global warming brought on by increased carbon dioxide production [source: Latham]. To get that added reflectivity, you could blast giant mirrors into orbit, paint more roofs white or create more cloud cover, which serves as a natural solar radiation reflector.

Latham and Salter's plan calls for these automated vessels to constantly blast seawater up into the air to form low-level cloud cover. What's the downside? Well, scientists are unsure what impact such atmospheric tinkering could have on the planet's weather patterns -- to say nothing of the costs involved. Still, you can't doubt the green agenda of robots designed to protect melting polar icecaps.

Keep reading for more links to the future of green technology.