For two weeks, rescuers at the Oklahoma City bombing site searched for survivors. If Kris Pister's research succeeds, that painful wait could be reduced to minutes.
Noise and trauma alone were enough to prevent rescuers from locating survivors buried and calling desperately for help, let alone tons of concrete. But imagine unleashing a thousand mechanical "crickets" to burrow through the rubble, each able to sense warm bodies among cold concrete or hear tiny cries, and find survivors in minutes. The locator cricket would then signal the nearest receiver by "chirping" loudly or sending a wireless signal to a monitoring station.
The cricket is just one of the cutting-edge devices from the world of micromachines, or as they are technically dubbed, microelectromechanical systems (MEMS), the largest area of research at the School of Engineering and Applied Science. a variety of these cutting-edge machines are being developed by Bill Kaiser, Chih-Ming ho, John Kim, Rajeev Jain and C.J. Kim. One of the technology's pioneers, assistant professor Pister directs an innovative research team in ambitious pursuit of micromachines, using a new "snap up" technique that could lead to those cheaply built, intelligent "insects." Often mistakenly referred to as "nanotechnology," which involves minute nanometer measurements and the manipulation of atoms, micromachines are manufactured at micron scale, which is to say, the hinges, gears and structures of the tiny silicon-based devices have dimensions of 10s or hundreds of microns (an average human hair is about 50 microns wide). Pister's systems will typically have micro-ears and micro-touch, tiny lasers that reflect off mirrors no wider than a strand of hair, and tiny brains of integrated circuits that can't be seen with the naked eye.
"We've jumped from macromachines to micromachines," says Pister. "And scale is the key, and the ability to make these devices with exactly the same processes used today to manufacture semiconductors." Because these standard processes are already common capability among high-technology manufacturing firms, making the transfer of any device into production relatively easy, Pister foresees huge advances in the not-too-distant future.
Besides rescue crickets, tiny "bugs" using accelerometers to detect the motion of intruders, infrared sensors to detect a person's heat and minuscule microphones to hear could be programmed to send a wake-up call, dial a homeowner's cellular phone or set off a security alarm. For the military, the same bugs could be sown on the battlefield to sniff for chemical gas, sense troop movements and locate heavy weapons.
And there will be important medical appli-cations. One device Pister's team has developed for UCLA doctors investigating the root causes of heart disease measures the strength of a single cell of heart muscle. Tiny prongs grasp the muscle and its contractions are accurately measured by strain gauges less than the size of a fly's eye.
"Laproscopies or polypectomies could be faster, which could save money and reduce discomfort," Pister notes. "Also, when looking for cancerous tissue, doctors could benefit from information provided by a micromachine sensor at the catheter tip." Because cancerous tumors are harder and hotter than benign tissue, sensors could locate tumors when they are very small.
Leaping technology barriers isn't the only innovative thing Pister's students accomplish. They are also becoming the first generation of experts trained in MEMS technology. "That's an important component to me," says Pister. "Research goes hand-in-hand with teaching. It's not often that students happen to be going through school when such a large new area of technology is under study. In 10 or 15 years, it is these students who will be heading up firms that manufacture the wide variety of micromachine products now envisioned."
— Bill Andrews |