New UMD Patent Advances Compact, High-Performance Phase Change Cooling for High-Flux Electronics

Congratulations to Center for Environmental Energy Engineering Co-Founder Michael Ohadi and alumnus Raphael Kahat Mandel (Ph.D. ’16) on receiving a new patent for a high-performance heat sink designed to cool high-flux electronics, where immense amounts of heat are concentrated in extremely small areas. The inventors’ “multi-stage, vapor-venting manifold microchannel (MMC) heat sink,” U.S. Patent 12,550,296, offers a compact, efficient cooling solution for high-power electronics, including data centers, AI processors and electric vehicles.

The approach uses coolants more effectively than existing MMC designs by relying on two-phase cooling and managing the resulting vapor buildup stage by stage. Although two-phase cooling can boost MMC heat-sink performance, it also leads to more vapor formation as the coolant evaporates. “Unless it is properly managed, the generated vapor reduces the heat transfer coefficient, undermining the desired high heat removal rates,” Ohadi says.

Ohadi and Mandel’s invention addresses this challenge by splitting the heat sink into multiple stages. Between stages, the coolant passes through a connecting passage where a vapor-permeable membrane allows vapor to escape while maintaining an optimum liquid coolant flow. The result is lower pressure drop, improved flow stability and more efficient heat transfer across the heat sink.

“This technology could significantly reduce cooling energy in data centers, enable higher-performance AI and HPC chips, and improve thermal management in compact, high-reliability electronics,” Ohadi says.

Ohadi leads CEEE’s Advanced Heat Exchangers and Process Intensification Consortium. Mandel earned his Ph.D. at UMD and then worked at the university as an assistant research scientist for CEEE and the Center for Advanced Lifecycle Engineering. In 2021, he joined Raytheon Technologies, where he conducts thermodynamics and heat transfer research.

Download the patent: “Multi-stage vapor-venting manifold-microchannel heat sink, and systems and methods for use thereof.”

Published May 19, 2026