Circuitry discovery could lead to beefier memory
SAN JOSE (AP) — For nearly 40 years, scientists have
speculated that basic electrical circuits have a natural ability to remember
things even when the power is switched off. They just couldn’t find it.
Now researchers at Hewlett-Packard Co. have proven them right,
with a discovery they hope will lead to memory chips that store more data but
consume far less power than those found in today’s personal computers and other
digital devices.
The newly discovered circuit element — called a memristor —
could enable cell phones that can go weeks or longer without a charge, PCs that
start up instantly, and laptops that retain your session information long after
the battery dies.
It also could challenge flash memory, which is now widely used in
portable electronics because of its ability to retain information even when
power is off. Chips incorporating the HP discovery would be faster, suck up
less power and take up far less space than today’s flash.
“It certainly looks promising,” said Wolfgang Porod, professor of
electrical engineering at the University of Notre Dame and director of the
university’s Center for Nano Science and Technology. “However, if it’s going to
be 100 times better or 1,000 times better (than today’s flash), it’s very hard
to say at this point.”
Scientists have suspected since the 1970s that along with the
three well-known elements of a basic circuit — the resistor, the
capacitor and the inductor — a fourth fundamental building block is
possible.
The memristor built by HP Labs researchers and reported Thursday
in the scientific journal Nature is made with a layer of titanium dioxide
sandwiched between two metal electrodes. The researchers discovered that the
amount of resistance it exerts depends on how much electric charge had
previously passed through it.
That characteristic gives the memristor an innate ability to
remember the amount of charge that has flowed through it long after the power
to it is turned off. That means the circuit itself can be built with a memory
function baked in.
Otherwise, data have to be stored in power-hungry transistors
configured for storage. That also takes up valuable real estate on
microprocessors or requires separate memory chips.
Some outside
researchers, however, said more study is required before the memristor upsets
the memory business.