Multiferroic alloy turns waste heat to energy

Engineering researchers at the University of Minnesota have discovered a new alloy capable of converting heat directly into electricity. 

Since heat is a large byproduct of electricity, this new alloy could make even everyday items much more energy efficient – perhaps even more so than an U.S. Department of Energy alloy that achieved a 25 percent conversion rate when created earlier this year.

The new multiferroic alloy was created at an atomic level and contains unusual elastic, magnetic and electric properties.

The alloy, Ni45Co5Mn40Sn10, achieves multiferroism by undergoing a reversible phase transformation where one solid turns into another solid.

It’s during this phase that the alloy achieves the magnetic properties that are then exploited in an energy conversion device. 

Without any heat, the alloy does not have any magnetic properties, however when exposed to even the smallest amount of heat it becomes strongly magnetic. When this happens, the alloy absorbs heat and produces electricity surrounding a coil.

Uses for this alloy are potentially endless. The material could be used to capture waste heat from a hybrid car’s exhaust and then produce electricity for charging the battery. 

On a larger scale, it could be used either for industrial and power plants’ rejected heat to help power parts of the building, or for capturing temperature differences in the ocean to produced electricity.

Even small-scale items like light bulbs and televisions could benefit from this alloy as they all produce surplus heat.

Funding for early research of the alloy came from a Multidisciplinary University Research Initiative (MURI) grant from the U.S. Office of Naval Research and research grants from U.S. Air Force and the National Science Foundation. 

The research team hopes to develop the alloy commercially as they see it as “the ultimate ‘green’ way to create electricity because it uses waste heat to create electricity with no carbon dioxide.”

Jasmine Greene, EarthTechling