Researchers at the VTT Technical Research Center have printed memory circuits directly on paper using roll-to-roll printing techniques and commercially available metallic inks.
The write-once-read-many (WORM) memories can be fabricated directly on the product or packaging using flexographic or inkjet printing machines.
Before writing, each memory bit is in the 1 state of high resistance. Writing a bit is performed by applying a low voltage across the bit, which in effect sinters adjacent silver nanoparticles and creates a path of least electrical resistance, turning the memory bit from a high resistivity 0 state to a low resistivity 1 state.
The lab printed a 150-meter roll containing more than 10,000 printed WORM memory banks on a thin heat-stabilized PET substrate.
The researchers, who previously demonstrated the sintering capability of the memory bits on paper, say inexpensive paper memories could be used in sensor data recording, product originality marking, playing cards, interactive packaging, and product information cards. For bigger memories that must limit the number of electrical contacts using a two-dimensional matrix structure of the bits, VTT's Ari Alastalo says researchers would need to implement a diode in series with each bit or employ more elaborate readout electronics to cancel crosstalk between the bits.
From EE Times
View Full Article - May Require Free Registration
Abstracts Copyright © 2015 Information Inc., Bethesda, Maryland, USA
No entries found