August 18, 2010
By Robin Donovan

Gang Chen in his office with a model of nanoporous silica.  With three years remaining on his grant, Chen hopes to create a structure that will bring phase change memory materials to the nanoscale.

In the second year of research funded by the National Science Foundation, Dr. Gang Chen is developing technology that will harness phase changes to revamp computer memory systems.  “We hope that we can improve this technology and make it faster and able to store more information,” he said, noting that phase change memory materials are already used in everyday devices such as Blu-Ray discs.

To build on this technology at the nanoscale, Chen synthesized hexagonally-structured nanoporous silica and germanium antimony telluride, or GST. When cooled and shrunken, liquid GST placed within this “honeycomb” solidifies faster and releases less heat.

“We could have a computer memory that’s at least 1000 times faster and store information at least 10 terabytes per square inch,’ he explained.  So far, Chen and his research group have synthesized the nanoporous silica and GST and learned how to control the size and composition of each material.

“A year from now we hope that we can put these individual components together. Basically, we have to fill the honeycomb with honey,” he said. A myriad of parameters, including temperature, influence how a combined structure would self-assemble.

The project has implications for technology based on phase changes, or a material’s change from a disordered, amorphous phase to an ordered crystalline state. “Unlike random-access memory, this memory is nonvolatile, which means the information stored inside will be there forever,” Chen said. That means future students may carry an entire library on a memory chip and read books through handheld devices.