|
|
 |
  |
| Sunday, 10 October 2004 |
 |
|
 |
Junior Observer |  |
| News Business Features Editorial
|
Can waves make electricity? While the ocean can be a great place to swim and play, it may also have another benefit. Some scientists think that waves could help make electricity. "Have you ever been out on a surfboard or boat and felt yourself being lifted up by a wave? Or have you ... jumped in the water and felt the rush of energy as waves crashed over you?" asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh in Scotland. "There is certainly a lot of energy in waves." Scientists are working to use that energy to make electricity. Most waves are created when winds blow across the ocean. "The winds start out by making little ripples, but if they keep on blowing, those ripples get bigger and bigger and turn into waves," Taylor said. "Waves are one of nature's ways of picking up energy and then sending it off on a journey." When waves come toward shore, people can set up dams or other barricades to block the water and send it through a large wheel called a turbine. The turbine can then power an electrical generator. The United States and a few other countries have started doing research on wave energy, and wave energy is already used in Scotland. "The resource is huge," said Janet Swain of the Worldwatch Institute in Washington, DC. "We will never run out of wave power." Plus, wave energy does not create the same pollution as other energy sources, such as oil or coal. Oceans cover three-quarters of the Earth's surface - that would make wave power seem ideal for creating energy throughout the world. But there are some drawbacks. Swain said that wave power still costs too much money. She also said that its effects on marine animals are still unknown. Plus, wave power could interfere with fishing and boat traffic. With more research, however, "many of these problems might be overcome," Swain said. Many experts think that finding new energy sources like wave energy is important. Traditional sources of energy like oil and gas may someday run out. "Demand for energy to power our TVs and computers, drive our cars and heat and cool our homes is rising rapidly throughout the world," Swain said. In the future when you turn on a light switch, an ocean wave could be providing the electricity! National Geographic Kids News Wearable robotics Just by getting dressed in the morning, you could jump 10 feet into the air, carry 150 pounds without getting tired, and throw a baseball faster than Roger Clemens. Such supercharged clothing is one possible product of a new technology called "wearable robotics". Designed to enhance a person's senses and skills, the apparatus could be as simple as a hearing aid. Or it could be as complex as a full-body suit that senses what you are going to do, then helps you do it better. "A Superman suit would be the ultimate in wearable robotics," says FranĜois Pin of the Oak Ridge National Laboratory in Tennessee. He is head of the robotics and energetic systems group. Superman and Superwoman suits are at least a decade away. But other applications for the technology are already in the works. A form-fitting robotic suit, or exoskeleton, could help a trooper on the battlefield. The U.S. Army is interested in using wearable robotics to help soldiers run faster, carry more gear, and be stronger in battle. The technology could also transform jobs that involve lifting heavy loads, rescuing survivors from the rubble of an earthquake, or collecting garbage. The first people to benefit from this technology, however, will probably be the elderly, handicapped, and injured. Researchers are developing artificial arms and legs, for example, that work almost as if they were living parts of a person's body. Someday, wearable robotics could make life easier for all of us. It might even be the secret ingredient for building the next generation of super-athletes. A robot is essentially a device that responds to a command. You have probably played with simple robots, such as toy cars or airplanes that respond to buttons you push on a remote control. Wearable robotics go a step further, says biomedical engineer Jacob Rosen. He heads the biorobotics lab at the University of Washington in Seattle. Instead of just receiving information through a wire or remote control, the robotic device also sends information back to its controller in a so-called feedback loop. Suppose you wore a sleeve that has sensors where your joints are. Every time you move your arm, the sleeve senses your movements and sends the information to a robot, which then moves its arm just as you did. When the robot hits or touches something, it sends a signal back to the sleeve and you sense the impact. Scientists are now working to wrap the robot around the person. Ideally, the sleeve, shoe or suit would do more than just sense your movements and send feedback. It would also help you do what you want to do. The problem is that ordinary sensors and feedback loops are too slow. "You always feel like you are dragging something behind you," Rosen says. This sluggishness defeats the purpose of the technology. One way to speed up response is to take advantage of the body's nervous system. Whenever you move, your brain sends signals through your nervous system to muscle tissue, which then allows you to walk, run, punch, pinch, blink, swallow, jump, whatever. Even though you perform many of these actions without even thinking about them, there is a tiny delay between command and action. Depending on the distance between the brain and the targeted muscle, it takes between 20 and 200 milliseconds for such a message to travel to its destination, Rosen says. That is just enough time for an electronic device to step in. Tiny computers implanted in the nervous system could intercept signals coming from the brain and tell the robot what to do, just as the muscle itself is about to do it. A well-designed device could even one-up the muscle and do the movement better. Rosen has already designed one robotic elbow joint and two shoulder joints that work in this way. He is now building a fully functioning robotic arm. Science for Kids |
|
| News | Business | Features
| Editorial | Security
| Politics | Produced by Lake House |
