HUMAN BATTERIES

In the near future, you might be an alternative fuel source. Scientists in the Asian country of Singapore have created a battery, powered by urine! Handy for powering all of those Christmas toys that are running out of power! The scientists were making computer "biochips" to test for diseases like diabetes, but they did not have a battery small enough to power the chips. Then they realised that the substance being tested with the chips—urine—could power the devices. Urine can power the battery because it contains negatively charged electronic particles called ions.

The battery consists of a piece of paper soaked in a chemical called copper chloride and sandwiched by strips of copper and magnesium. A coating of see-through plastic protects the battery. When urine enters the battery through a small slit, a chemical reaction starts that generates electricity. The battery creates the same energy as a standard AA battery (1.5 volts) and can run for about 90 minutes. The same technology can use other body fluids to create power. Ki Bang Lee, one of the inventors of the urine battery, said it could also run on tears, blood, and saliva. Lee gave an example of the possibility of powering a cell phone with saliva to make a call during an emergency. Daniel Kammen of the Renewable and Appropriate Energy Laboratory at the University of California-Berkley said that the battery technology "can do all kinds of things". Soon they could be powering laptop computers, MP3 players, televisions, and even cars! Kammen says the wide number of applications for cheap and efficient biofluid-powered batteries illustrates the value of basic research. "Investigation leads to innovation," he said.


FLY POWER
Robots usually run on batteries, right? Well not all of them. Scientists in England have built a series of small robots that get their energy from dead flies, rotten apples, or sugar. One robot, called Slugbot, was even designed to hunt garden slugs for dinner! Scientists at the Bristol Robotics Laboratory want to invent robots that can operate for long periods of time in dark, dirty, or dangerous places. Many of those spots, like the seafloor or Antarctica, don't have electrical sockets. So inventor Chris Melhuish came up with a better idea: Build robots that get their energy just like animals do—by hunting and eating food from their environment. The robots digest their grub in a series of stomach-like devices called microbial fuel cells that are full of bacteria The bacteria do the real eating, munching dead flies or other food fed into the fuel cells. As the bacteria chew, they release electrons. Electrons are charged particles that flow to form electricity. One robot, called Ecobot II, could run for 12 days on a diet of eight flies! (You'd still get a lot more power from one AA battery, though.) Melhuish says his team is now working on a new and improved robot, called Ecobot III, which will have a better digestion system. It seems that after an eight-fly dinner, Ecobot II couldn't get rid of the leftover "waste."

Environmental.

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