A thermal scientist for a sustainable future

Zhengmao Lu, a newly appointed Tenure Track Assistant Professor at EPFL's School of Engineering, stands at the intersection of thermal science, interface engineering, and materials science. Lu's work blends fundamental science and practical engineering, focusing on interfacial thermal phenomena and their applications in energy and water purification. As the world heats up, he is currently exploring sustainable solutions for temperature regulation of buildings using passive cooling systems in rooftop installations.

It's about creating systems for better energy efficiency and water purification – pivotal for our society.

Lu hails from the halls of the Massachusetts Institute of Technology (MIT), completing both his PhD and post-doctoral work at the renowned American institution. "During my time at MIT, I delved deeply into thermal science, exploring how new materials can revolutionize traditional methods. It's about creating systems for better energy efficiency and water purification – pivotal for our society." Highlighting the evolution of his research focus, "My PhD was about cooling electronics, but during my postdoc, I shifted towards larger-scale applications like building cooling.”

Lu's research at EPFL is opening new frontiers in the realm of sustainable technology, particularly in the field of passive cooling. Explaining the essence of this concept, Lu states, "One project is about generating cooling from the sky. If you have a surface that is solar reflecting and Infra-Red (IR) emissive, you can effectively generate cooling just by sitting there." Instead of a power source to run central cooling system, for example, his technique harnesses the inherent properties of materials and the natural environment to facilitate cooling.

Lu explains, "We're working on generating cooling passively, utilizing the sky as a heat sink in rooftop installations. By developing surfaces that reflect solar energy while emitting infrared radiation, we can effectively cool by simply interacting with the universe's vast cold space."

Lu further details the scientific basis of his work, highlighting the atmospheric dynamics that make passive cooling viable: "Because our Earth has this interesting atmosphere spectrum that is kind of transparent in the mid IR range, any thermal radiation generated by things around room temperature can release into the sky without much loss." This transparency allows surfaces designed by Lu to emit infrared radiation effectively into space, facilitating cooling even during daylight hours. Such innovation not only exemplifies cutting-edge science but also underscores a commitment to environmental sustainability, addressing the pressing need for energy-efficient cooling solutions in an increasingly hotter world.

We can effectively cool a building by simply interacting with the universe's vast cold space.

Lu's research goes beyond passive cooling to include dynamic thermal processes in general—with a wide range of applications. He elaborates, "My primary interest lies in understanding energy transfer during phase changes, like evaporation, boiling, or condensation. These are not just scientific phenomena but are integral to practical applications such as power generation and desalination."

Lu aims to apply his deep understanding of thermal processes in his teaching role at EPFL. His first class at EPFL will be a Spring semester 2024 Master’s class intitled: Two-phase flows and heat transfer. Anticipating his teaching role, Lu expresses enthusiasm: "It's a subject deeply connected to my research, and I'm passionate about sharing this knowledge, particularly in the context of sustainable energy and environmental solutions."

In both teaching and research, Lu emphasizes the importance of fundamental research for long-term impacts: "To achieve breakthroughs, we need to understand the fundamentals. I'm interested in the molecular-level physics of phase change phenomena, which could revolutionize energy generation and usage, particularly in sectors like nuclear power where land constraints are significant."

To achieve breakthroughs, we need to understand the fundamentals.

Zhengmao Lu's path from MIT to EPFL has been defined by his commitment to understanding and applying thermal phenomena for global sustainability. His research, combined with his drive to educate the next generation of engineers, positions him as a key figure in shaping the future of sustainable technology and environmental stewardship.