Spark plasma sintering creates materials to capture waste heat

Mike Reece has been developing thermoelectric nanomaterials that can convert waste heat into useful electrical energy. There are many possible applications for this technology. For example, it could be used in devices designed to harvest heat from car exhausts and transform it into electricity, which in turn could power the car’s air conditioning. It could also be useful in deep space missions, where solar energy cannot be relied on. Thermoelectric nanomaterials could be used to transform energy from encapsulated radioactive heat sources into electricity.

The ImpactQM funding enabled an initial collaborative industrial project involving Mike and, a then post-doctoral research assistant, Haixue Yan. “Within weeks we were producing new thermoelectric materials,” Mike recalls. “It quickly opened up a major research area that is contributing to the larger research effort at QM to develop energy related materials that contribute to reducing energy consumption and pollution.

“The materials that I am developing are best made by densifying powders at high temperatures (usually higher than 1,000°C).” Mike explains. “This process, known as sintering, produces polycrystalline materials that consist of small grains of materials joined together. This is how most ceramic materials are made, including household items such as plates or high technology electronic materials used in sensors.

“As a result of the ImpactQM funding, we have developed expertise in making these materials and are now developing new materials that will hopefully one day find commercial applications,” says Mike.”

Nanotechnology gives us an insight into how materials behave at small length scales: in some cases their properties improve, and in others they are degraded. Being able to manipulate materials at the nanoscale has opened up possibilities for developing new and improved materials for new applications.

QM spin-out company, Nanoforce Technology, is developing processing routes to produce nanostructured materials and composites. This includes the first Spark Plasma Sintering (SPS) furnace in the UK.

The SPS process involves rapid heating. Mike says, “It is much faster than conventional sintering. Instead of hours or days to process materials, it now takes minutes.”  This unique capability was key to the success of the Impact QM project.

What started as a single project has grown into an ongoing relationship between QM and European Thermodynamics Ltd (ETL).

Mike says, “it has opened up many new research and collaboration opportunities. Two PhD students are currently involved with projects with ETL, and I’m working with them on an ongoing basis as part of a Royal Society Industry Fellowship.”

“My research has always been applications-focused, but the close partnership with ETL has brought this even more to the fore. I have many meetings with potential end users of the technology, and this really focuses your attention on what is actually needed to produce commercially successful material.”