Laurence P. Sadwick was skeptical two years ago when a mild-mannered inventor from Pecos, N.M., brought him a novel design for a computer memory chip. The inventor, Richard M. Lienau, and the start-up firm that he had found to back him, named Pageant Technologies, made remarkable claims. These new chips, they said, could hold data even when the power went out--for many years, if need be. They would work five to 10 times faster than the so-called dynamic random-access memory (or DRAM) chips used in computers today. Yet the new chips should cost no more to make: only minor changes to existing production lines were needed. The secret ingredient that made all this possible, Lienau said, was an array of minuscule magnets.
"I gave them a hard time. I didn't trust them," recalls Sadwick, an electrical engineer at the University of Utah. After all, academic groups had tried since the mid-1980s to replace the capacitors that record information in DRAM with micron-size bits of ferromagnetic metals such as alloys of iron, nickel and cobalt. Capacitors lose their charge--and their data--unless they are refreshed every few milliseconds. Magnetic films, on the other hand, don't suffer such amnesia, which is why hard disks are coated with them. But it is one thing to measure tiny magnetic fields as they pass beneath a single moving head, as disk drives do. Building a sensor right next to each one of millions of magnetic bits is much harder.