Developments to Watch
You've Got Mail--20,000 Leagues under the Sea
Davy Jones's locker might soon be a popular e-mail address. The U.S. Navy has demonstrated that wireless access to the Internet can extend to underwater domains. At the end of May, the submarine USS Dolphin sent the first subsea e-mail while "surfing" 400 feet deep.
Sending digital data through the ocean is tricky because, ironically, water is such a good transmission medium. Since sound waves can travel hundreds of miles, the ocean is flooded with noise. Sifting out the sound of a given digital bit is complicated by the fact that the same digital-bit sound can arrive many times: Echoes also travel long distances under water, bouncing off sub-sea cliffs and canyons and boundaries between water layers of different temperatures.
Using special acoustic modems from Benthos Inc. in North Falmouth, Mass., the Dolphin sent Internet mail through several miles of noisy water. Buoys outfitted with savvy Benthos software filtered out the traffic, then relayed it via satellite to shore. The data crawled at just 2,400 bits per second, but Benthos President John L. Coughlin says his next-generation modems will run four times as fast.By Otis Port; Edited by Ellen LickingReturn to top
How Geckos Stick Like Glue--without Goo
Forget duct tape. Never mind Crazy Glue. If you need to get a grip, try gecko feet. A team of biologists and engineers, led by Robert J. Full of the University of California at Berkeley, have discovered what gives Tokay geckos the ability to casually stroll across the ceiling. The little lizards use a kind of atomic energy to tap into the molecular structure of the surfaces they navigate.
The findings, published in the June 7 issue of Nature, have important practical applications. Engineers at iRobot in Somerville, Mass., are building tiny robots with wheel surfaces similar to those of gecko feet. The robots, which can scale walls and climb upside-down, might be useful in emergency situations. Engineers elsewhere are hoping to create a super-strong tape for use underwater and in outer space.
Unlike tree frogs, which secrete a glue-like substance that adheres to surfaces, the secret to a gecko's holding power is in the construction of its feet. Each foot is covered with a half-million fine hairs called setae; these hairs are a tenth of the diameter of a human hair. Each seta is crowned with 1,000 spatulae--submicroscopic hairs that look like fly swatters. There are more than one billion spatulae per gecko foot, and each one can form a weak bond with the surface. Together, they create an adhesive force strong enough to lift a 45-pound child.
Gecko feet hang on in a vacuum and under water. And geckos have good hygiene: Their feet are self-cleaning--they don't collect dirt or dust.Edited by Ellen LickingReturn to top
Hands-on Exams of Faraway Patients
Doctors' hands are two of their most important tools. Just by touching a patient, they can often detect signs of disease or injury. There's just one problem: Both the physician and the patient must be in the same place at the same time for this diagnosis to work.
That may not be true for much longer. Researchers at the State University of New York at Buffalo are developing a virtual-reality system that stores the sensations a doctor experiences when examining a patient. The data are collected by tiny sensors in the fingertips of a special virtual-reality glove and downloaded to a workstation set up to receive video streaming data as well as examination data. At present, the information is sent directly to the computer terminal via a cable, but researchers anticipate using the Internet for real-time transmission.
If the technology works, it could be a life-saver for victims injured in remote or rural locations. Trauma surgeons could make their diagnoses while the victim is still in the field and immediately begin operating once the patient reaches the hospital.Edited by Ellen LickingReturn to top