Washington, June 20 : An IIT-Madras alumnus, currently associated with Purdue University, has revealed that he and his colleagues are working on a miniature refrigeration system that will be small enough to be used inside laptops and personal computers.
Suresh Garimella, Director of the Cooling Technologies Research Center based at Purdue, says that such a cooling technology may help boost performance of the machines while shrinking their sizes. As compared to the existing cooling systems that use a fan to prevent computer chips from overheating, he says, the miniature refrigeration would dramatically increase how much heat could be removed.
The researcher has revealed that his research focuses on learning how to design miniature components called compressors and evaporators, which are critical for refrigeration systems.
His team has already developed an analytical model for designing tiny compressors that pump refrigerants using penny-size diaphragms, and validated it with experimental data.
Suresh has revealed that the elastic membranes are made of ultra-thin sheets of a plastic called polyimide, and coated with an electrically conducting metallic layer that allows the diaphragm to be moved back and forth to produce a pumping action using electrical charges, or "electrostatic diaphragm compression".
He also says that another related research has made his team the first to precisely measure how a refrigerant boils and vaporizes inside tiny "microchannels" in an evaporator, and to determine how to vary this boiling rate for maximum chip cooling.
"We feel we have a very good handle on this technology now, but there still are difficulties in implementing it in practical applications. One challenge is that it's difficult to make a compressor really small that runs efficiently and reliably," said Garimella, who led the research with Eckhard Groll, a professor of mechanical engineering.
The researchers say that new types of cooling systems will be needed for future computer chips that will likely generate 10 times more heat than today's microprocessors.
Telling about a key advantage the miniature refrigeration would have over other cooling technologies, Groll said: "The best that all other cooling methods can achieve is to cool the chip down to ambient temperature, whereas refrigeration allows you to cool below surrounding temperatures."
According to experts, the ability to cool below ambient temperature could result in smaller, more powerful computers as well as improve reliability by reducing long-term damage to chips caused by heating.
Groll, however, points out that a complication before them is that the technology would need many diaphragms to operate separately to pump a large enough volume of refrigerant for the cooling system.
"So you have an array of 50 or 100 tiny diaphragm compressors, and you can stack them," he said.
Garimella, however, points out that the computational model they have developed for designing the compressor shows that the it is feasible to design a prototype system small enough to fit in a laptop.
He says that the model enables the engineers to optimise the design, and determine how many diaphragms to use and whether to stack them parallel to each other or in series.
The researchers also have to determine how to make such devices at low cost.
The research will be detailed in two papers being presented during the 12th International Refrigeration and Air Conditioning Conference and the 19th International Compressor Engineering Conference on July 14-17 at Purdue.