Development of next-generation magnetocaloric materials

The future of the fuel cell market depends on developing new infrastructure for the preparation, transportation, and storage of hydrogen. Liquefaction maximizes storage and transport efficiency, but is particularly challenging in distributed systems because of the extremely low temperatures required. While fuel reformer technology is constantly improving, storing and transporting the fuels for on-demand use remains a problem. Project approach: Nanohmics proposes to develop a novel magnetocaloric metamaterial for hydrogen liquefaction. The innovation is to drive the cooling effect using a controlled micromechanical structure rather than tailoring intrinsic materials properties. By introducing an artificial phase transition in the metamaterial, it’s possible to use ferromagnetic materials like nickel to accomplish the cooling, or alternatively to enhance the efficiency of Gd-based alloys. Phase I tasks: A modeling effort will provide performance bounds and guidance on the metamaterial geometry. Microfabricated test coupons will provide reduce the development risk. Measurements of magnetocaloric enhancement will provide proof-of-concept. Commercial Applications and Other Benefits: An enhanced magnetic refrigeration technology will reduce dependence on fossil fuels by making hydrogen a more viable fuel technology. Improving the liquefaction process will increase the international distribution and storage potential, allowing hydrogen to be used more readily in fuel cells and generator applications. Additionally, improvements in magnetic refrigeration technology will enhance research and laboratory facilities that require low-temperature instruments. As a solid-state refrigerant, it does not require ozone-depleting gases and may find application in commercial refrigerators. Key Words: Magnetocaloric materials, magnetic refrigeration, metamaterials