Colloquium Series: Po-Chun Hsu, Duke University

Dynamic multispectral heat management for energy and health

Abstract:

Black body radiation is one of the most ubiquitous forms of energy. The scalability of Planck’s Law and Maxwell’s equations enable us to describe both sunlight and ambient thermal radiation in a similar and interconnected way. As climate change worsens, pushing the scientific understanding and engineering capability for controlling light and heat is the key for future energy sustainability. For example, 12% of total energy consumption in the US is for indoor temperatures heating and cooling, which shows the inherent tradeoff between energy efficiency and personal thermal comfort. In this talk, I will present several materials and photonic designs that can perform radiative thermoregulation for better building energy efficiency and personal health. The first part will introduce the concept of “personal thermal management”. I will start with single-mode radiative heating and cooling textiles and then demonstrate the dual-mode and multi-mode electrochromic textiles, which can dynamically shield the human body from fluctuating ambient temperatures to serve as potential digital therapeutics and preventive medicine. The second part will focus on buildings and general objects. Our recent progress of the mechanochromic device can modulate all three phenomena—reflection, absorption, and transmission—for all-surface radiative heat management and thermal camouflage. For outdoor scenarios, I will explain our dynamic smart building envelopes that can switch between radiative cooling and solar heating and utilize both renewable energy sources to reduce year-round fossil fuel consumption.

Bio:

Po-Chun Hsu joined Duke University in January 2019 as an assistant professor in the Department of Mechanical Engineering and Materials Science where his lab focuses on light and heat management, nanophotonic materials, energy sustainability and storage, and wearable technology. Dr. Hsu received his PhD in Materials Science and Engineering from Stanford University in 2016 and as a postdoctoral researcher in Mechanical Engineering also at Stanford. Dr. Hsu has co-authored 57 journal papers with 12000 citations and h-index of 39. His research of nanoporous radiative cooling textile was selected as one of the “Ten World-Changing Ideas” by Scientific American. His group aims at investigating fundamental science questions that can lead to solutions for real-world engineering problems.