Hewlett-Packard Co.'s HP Labs has designed a crossbar switch that may one day allow the company to pack the power of a traditional microprocessor arithmetic logic unit into just a few square microns. Current bus structures applied at the nanoscale are akin to trying to drain a swamp with a soda straw � domains measuring a few nanometers across are just too much of a bottleneck for traditional input/output schemes. Hewlett-Packard (Palo Alto, Calif.) claims that its crossbar switch design has broken that bottleneck by reducing the I/O problem by 128 to 1, while providing a bistable latching architecture for cascading any number of layers of nanoscale memory and logic. "A single pair of lines can now control 100 or more switches at the same time," said Phil Kuekes, senior architect at HP Labs' Quantum Science Research group. "Since our latches can also restore the logic levels of these bits, we can now gang together any number of layers of logic and memory functions. Next we want to show we can perform traditional logic functions with crossbar switches, but at a density you can't achieve today with transistors � such as packing a 128-bit ALU into just a few square microns."