US Patent 7242215 - Nanoscale hysteretic resistor latch

http://www.freepatentsonline.com/7242215.html

The term "hysteresis" is most often used in reference to magnetic materials and generally refers to an effect lagging cause phenomena useful for data storage. However, various companies including HP, Micron Technologies, Ovonics, etc. are working on using molecular, polymer, or chalcogenide-based materials to achieve hysteresis of electrical resistance as well. These materials are useful in creating a variety of switching and logic devices and may be integrated in nanowire based electronic structures using printing based fabrication that can be far cheaper than the standard fab methods used in electronics. As more companies begin to be attracted to these materials it is possible that hysteretic resistance materials may one day rival semiconductors as the leading material in electronics. This patent from HP teaches a basic latching circuit using hysteretic resistance materials.

1. A nanoscale latch that stores a logical value, the nanoscale latch comprising: a nanoscale control-voltage input line; a nanoscale input/output signal line; and a nanoscale hysteretic resistor linking the control-voltage input to the input/output signal line that represents a first logic value when in a low-impedance, closed state and that represents a second logic value when in a high-impedance.