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Cooling high-speed computers

- Wits University

The School of Mechanical, Industrial and Aeronautical Engineering is about to make headlines for the development of new technology to cool high-speed computers.

Under the leadership of Professor Ionel Botef, who recently set up Africa’s first Supersonic Spray Technology laboratory at Wits, the team has devised a micro heat sink for computers that could operate above 3GHz by using a process called cold spray technology.

The result is a porous copper micro heat sink that is 50 times smaller than those currently used and which could cool computers much more effectively. The research paper on the development of this technology by PhD student Agripa Hamweendo and Botef has led them to apply for a patent licence on the manufacturing process.

“We are currently busy with a paper for an ISI accredited journal but we are going to apply for a patent for the micro heat sink as a product itself too, before we submit the paper,” says Hamweendo.

“Postgraduate students have three other patents in the pipeline.”

The manufacturing process of the heat sink involves the cold spray technology, in which various powder materials are applied by bombarding the substrates at a high velocity of between 300 and 1 200 meters per second. The micro heat sink was created by spraying multiple layers of copper onto each other thereby creating multiple micro channels that serve as small ventilation shafts.

“The process can fabricate micro heat sinks with improved flow characteristics within micro channels, improved channel aspect ratios and multiple flow arrangements at the inlet and outlets,” explains Botef.

The cold spray process is highly versatile and can be used from the manufacturing of micro systems for electronics to the repair of large equipment such as the turbines in power stations.

Botef, who initially qualified as a mechanical engineer, is passionate about multidisciplinary studies and holds his PhD in Electrical and Information Engineering.

“That was the best decision that I have ever made as it gave me an opening into another world.”

When Botef first started out with the cold spray at Wits, he had to knock on the doors of his colleagues across campus to persuade them of the importance of the technology.

“Since then we have built an integrated Cold Spray and 3D Printing Laboratory and an academic team from various disciplines, including 37 postgraduate students from countries such as the Congo, Nigeria, Zambia, Zimbabwe and South Africa,” he adds.

Botef has worked in the aerospace industry with the likes of Rolls-Royce.

He is widely published in accredited journals and is internationally sought after for his specialist expertise. “Our mission is to build capable people who can act at the right time and who make critical decisions timeously to make a real difference in the world,” he concludes.