
Speaker: Po-Chun Hsu: University of Chicago: Electrochemically Active Metasurfaces and Radiative Thermoregulating Materials for
Human-Building-Energy Nexus
Presented 1/16/2025, hosted by Yiyang Li
Synopsis by Zach Pizzo, 2nd Year PhD Candidate in Chemical Engineering
The Human-Building-Energy Nexus, which involves the interplay between human thermal comfort, building heating and cooling, and energy sustainability, is critically important for shaping the future of modern society. The seminar, titled “Electrochemically Active Metasurfaces and Radiative Thermoregulating Materials for the Human-Building-Energy Nexus,” was presented on January 16th, 2025, by Professor Po-Chun Hsu, Assistant Professor at the Pritzker School of Molecular Engineering, University of Chicago.
In the first portion of the talk, Professor Hsu highlighted his group’s recent work published in Science, titled “Spectrally Engineered Textile for Radiative Cooling Against Urban Heat Islands.” This research addresses the challenge of mitigating urban heat island effects by developing a novel spectrally engineered hierarchical textile (SSHF). The SSHF features dual-function emissivity: the outward-facing side selectively emits radiation in the atmospheric transmission window, facilitating effective heat dissipation into outer space, while the inward-facing side exhibits broadband emissivity to enhance cooling near the body. This innovative design minimizes heat absorption from surrounding surfaces, such as the ground and buildings. Experimental results demonstrate that the SSHF remains 2.3 °C cooler than a broadband emitter when oriented vertically and 6.2 °C cooler than the ambient temperature when oriented horizontally. Additionally, the textile’s excellent wearability makes it a promising solution for personal cooling in densely populated areas. However, there are limitations regarding its relatively high cost and scalability that still need to be addressed before commercialization can be considered.
In the second portion of the talk, Professor Hsu discussed his group’s work published in Nature Sustainability, titled “Dynamic Electrochromism for All-Season Thermoregulation.” This research focuses on a novel building material envelope design that employs electrochromism to dynamically tune thermal emissivity. The system, based on a graphene electrode with reversible copper electrodeposition, achieves emissivity values ranging from 0.07 to 0.92, offering significant flexibility for thermal regulation. Simulations indicate that this design could reduce HVAC energy consumption by up to 43.1 MBtu annually, highlighting its potential for energy-efficient building envelope applications.
Professor Hsu also referenced related work published in ACS Energy Letters, which described the development of a flexible ultra-wideband transparent conducting electrode leveraging electrochromism. This system demonstrated emissivity tunability from 0.12 to 0.94, enabling advanced heat management through synergistic solar and mid-IR control. Lastly, the talk touched on the group’s recent progress in designing high-conductivity polyaniline polymers for wearable thermoregulation and dynamically tunable broadband mid-IR meta-emission.
Reflecting on this seminar, I found Professor Hsu’s work particularly inspiring as it bridges fundamental materials science with practical applications that address both individual and societal energy challenges. The integration of radiative cooling materials and dynamic emissivity into everyday infrastructure aligns with the broader goal of enhancing energy efficiency while mitigating the effects of climate change. From the perspective of my own research on improving the efficiency, stability, and scalability of perovskite solar cells, this seminar highlighted the importance of pursuing interdisciplinary solutions to global energy challenges. While my work focuses on more effectively harvesting solar energy, Professor Hsu’s innovations highlight how complementary approaches—such as reducing energy consumption in buildings and enhancing personal cooling—are also essential for achieving a sustainable energy future. These efforts remind me of the interconnected nature of the energy landscape, specifically that every technological advancement contributes to the common goals of reducing demand for fossil fuels and improving energy equity worldwide.