Reversible Solar Heating and Radiative Cooling Devices via Mecbhanically Guided Assembly of 3D Macro/Microstructures

• Published in: Advanced materials (Weinheim) 2024-06, p.e2400930
• Main Authors: Lee, Su Eon, Seo, Junyong, Kim, Simon, Park, Jun Hyun, Jin, Ho Jun, Ko, Janghun, Kim, Jang Hwan, Kang, Heemin, Kim, Jin-Tae, Lee, Heon, Lee, Bong Jae, Kim, Bong Hoon
• Format: Article
• Language: English
• ISSN: 1521-4095
• DOI: 10.1002/adma.202400930

Solar heating and radiative cooling are promising solutions for decreasing global energy consumption because these strategies use the Sun (∼5800 K) as a heating source and outer space (∼3 K) as a cooling source. Although high-performance thermal management can be achieved using these eco-friendly methods, they are limited by daily temperature fluctuations and seasonal changes because of single-mode actuation. Herein, reversible solar heating and radiative cooling devices formed via the mechanically guided assembly of 3D architectures are demonstrated. The fabricated devices exhibit the following properties: (i) The devices reversibly change between solar heating and radiative cooling under uniaxial strain, called dual-mode actuation. (ii) The 3D platforms in the devices can use rigid/soft materials for functional layers owing to the optimized designs. (iii) The devices can be used for dual-mode thermal management on a macro/microscale. The devices use black paint-coated polyimide (PI) films as solar absorbers with multilayered films comprising thin layers of polydimethylsiloxane/silver/PI, achieving heating and cooling temperatures of 59.5 and -11.9 °C, respectively. Moreover, mode changes according to the angle of the 3D structures are demonstrated and the heating/cooling performance with skin, glass, steel, aluminum, copper, and PI substrates is investigated. This article is protected by copyright. All rights reserved.