-- AeroVironment, builder of the Dragon Eye and other unmanned aerial vehicles (UAVs), has notched a record: flying the first UAV fueled with liquid hydrogen. The slender, 50-foot-wingspan plane has eight electric engines powered by fuel cells, which generate electricity from a chemical reaction between hydrogen and oxygen in the air. In 2001 the plane soared to 97,000 feet, a record for a prop plane. AeroVironment says it will soon offer UAVs that can stay aloft for more than a week. Applications could include patrolling borders, tracking hurricanes, and -- using two UAVs in rotation -- serving as a low-cost alternative to satellites for local telecom networks. Searching for terrorist hideouts and arms caches may soon get a sonic boost. U.S. Army researchers at Fort Huachuca, Ariz., are working with Silicon Graphics Inc. (SGI
) on sonar for use on land. Like the naval variety, it could be active -- sending sound waves pinging through the ground, which could also reveal land mines -- or passive, sensing unnatural sounds.
The original aim was to listen passively with a king-size stethoscope for anomalous sounds, which an SGI computer in a Humvee would analyze to identify, say, a hidden factory or command bunker. In tests, the system easily hears a pump being used to pull down fresh air for people to breath. And from the way the pump's sound changes as it passes through a bunker's walls, "we can tell how big the bunker might be and what it's made from," says SGI exec Bill Bartling.
In mountainous terrain, cave hideouts could be detected with dart-like sensor-transmitters that penetrate the earth when dropped from a plane or shot from a cannon. If no telltale sound is heard, the Army could switch to active mode -- shelling the mountain, then searching the seismic echoes for signs of a drastic change in density, indicating a cave. Among the genetic traits that distinguish different canine breeds, there's one that dog owners wish science would improve on -- predisposition to disease. Dog lovers take heart: Researchers at Imperial College London are exploring the canine genome in collaboration with Britain's Kennel Club, which has more than a century's worth of meticulous records. By correlating these data with analyses of DNA swabs from dogs' mouths, Imperial's David Balding and Federico Calboli hope to learn why certain breeds are more disease-prone. Their findings could point the way to better foods and veterinary drugs and help breeders avoid crosses that could make matters worse. And because dogs and people share many diseases in common, the work also promises to help human health. Clinical trials over the last seven years showed that stroke patients with impaired arm movements improved twice as quickly when a robotic arm developed at Massachusetts Institute of Technology augmented their exercise efforts. Now, MIT aims to develop a whole family of physical-therapy robots.
The latest one is a prototype dubbed Anklebot. It fits around the lower leg and challenges patients to move their ankles in ways that will improve balance and gait, since stroke victims are often plagued by falls.
Anklebot's tactic is like that of the earlier MIT-Manus robot arm: A video screen shows an exercise, such as connecting dots to draw a square. Depending on how the patient responds, the robo-arm moves the person's arm through the entire task or just helps it complete the exercise.
Similar bots are being developed for the shoulder, elbow, wrist, and hand. And MIT has teamed up with the Baltimore Veterans Administration to create a gym where future robots will put humans through their paces.