After flexible displays, the memory chip is the latest electronic component to get twisted and bent. Researchers at the National Institute of Standards and Technology have developed a flexible memory device that they say is inexpensive and can be easily manufactured.
“We have fabricated a lightweight memory device,” says Nadine Gergel-Hackett, one of the researchers on the project, “that uses transparencies seen in overhead projectors as the material for its flexible sheet.”
Flexible components are a promising new area for electronics makers who envision using them for bendable, flexible, rollable, or merely curved devices that contain electronic circuits. Current silicon and circuit-board technology requires components to be flat and rigid. But flexible components would open up a whole new class of possibilities. For instance, they could be used to create small medical sensors to monitor heart rate or blood sugar.
Though some flexible components have already been created, it’s been a challenge to create a pliable memory chip that is inexpensive to produce, says Gergel-Hackett.
Gergel-Hackett and her colleagues took polymer sheets and deposited a thin film of titanium oxide on their surfaces. To deposit the titanium oxide, they used a sol gel process that consists of spinning the material in liquid form and letting it set, similar to how gelatin is made. They added electrical contacts and created a flexible memory switch that operates on less than 10 volts.
The device can also maintain its memory when power is lost and can function even after being flexed more than 4,000 times, according to a paper in the upcoming July issue of IEEE’s Electron Device Letters journal. The paper does not specify what the capacity of the prototype flexible memristor is.
What also makes this bendable memory device special is that it has the characteristics of a memristor– a new component for electronic circuits. The memristor or memory transistor is seen, along with the three other widely known elements–the capacitor, the resistor and the inductor–as a fundamental circuit element. A memristor changes its resistance depending on the amount of current that flows through it, allowing it retain the resistance even after the power is turned off.
The flexible memristor is still in the prototype stage and faces some challenges before it can be ready to market. Reliability and consistency between the different devices made are two issues, says Gergel-Hackett. But because of the fabrication process, she hopes some day it can be as easy to print a flexible memory component as it is to print a slide on a transparency.
Photo: Flexible memory prototype
