Gaithersburg, ND – Scientists at the Institute of Standards and Technology (NIST) have found a way to build a flexible memory component out of inexpensive, readily available materials.
The new device has potential applications in medicine – sensors worn on the skin, for example – and for easily-dropped gadgets such as MP3 players. Though some flexible components exist, flexible memory has remained elusive, according to NIST researchers.
Intriguingly, the device also appears to possess the characteristics of a memristor, a fundamentally new component for electronic circuits that industry scientists developed in 2008.
The researchers took polymer sheets — the sort that transparencies for overhead projectors are made from — and experimented with depositing a thin film of titanium dioxide on their surfaces. Instead of using expensive equipment to deposit the titanium dioxide, it was deposited by spinning the material in liquid form and letting it set. By adding electrical contacts, the team created a flexible memory switch that operates on less than 10V, maintains its memory when power is lost, and still functions after being flexed more than 4,000 times.
What’s more, the switch’s performance bears a strong resemblance to that of a memristor, a component theorized in 1971 as a fourth fundamental circuit element (along with the capacitor, resistor and inductor). A memristor is, in essence, a resistor that changes its resistance depending on the amount of current that is sent through it — and retains this resistance even after the power is turned off. Industrial scientists announced they had created a memristor last year, and the NIST component demonstrates similar electrical behavior, but is also flexible.
“We wanted to make a flexible memory component that would advance the development and metrology of flexible electronics, while being economical enough for widespread use,” says NIST researcher Nadine Gergel-Hackett. “Because the active component of our device can be fabricated from a liquid, there is the potential that in the future we can print the entire memory device as simply and inexpensively as we now print a slide on an overhead transparency.”
The research is reported in the July 2009 issue of IEEE Electron Device Letters.