The core of this transformative technology lies in the scalable transparent radiative cooling (STRC) film, which seamlessly integrates into vehicle glass surfaces. Unlike conventional solutions such as Low-E coatings or tinting films that primarily block incoming solar radiation yet struggle with expelling internally accumulated heat, the STRC film operates on a radically different physical principle. It harnesses the power of radiative cooling, a passive mechanism whereby thermal energy from a warmer surface is emitted as infrared radiation into the cold outer space, effectively reducing heat accumulation without the need for electrical inputs.

Technically, the STRC film is a sophisticated multilayer structure engineered to maintain an impressive over 70% transmittance in the visible light spectrum, ensuring interior brightness and visibility remain uncompromised. Simultaneously, it selectively reflects near-infrared wavelengths—the primary components of solar heat—while efficiently emitting mid-infrared radiation from inside the vehicle to the ambient environment. This dual functionality represents a delicate balancing act of optical properties, achieved through advanced materials science and precise nanofabrication techniques.

One of the remarkable aspects of this research is its scalability and applicability to real-world conditions. The team performed extensive field tests, mounting the STRC film on sedan windows and evaluating performance under dynamic driving and stationary parking scenarios across seasons. Results confirmed consistent temperature regulation, signifying the technology’s resilience against variable solar intensities, atmospheric humidity, and operational modes. These findings represent a critical validation beyond laboratory prototypes, affirming the film’s readiness for commercial adoption.

The implications for energy consumption in automotive air conditioning systems are profound. By intercepting solar heat before it permeates the cabin and facilitating thermal emission, the STRC film substantially reduces the load on vehicle cooling systems. Empirical data indicated a more than 20% decrease in air conditioner energy usage, which translates into extended driving ranges for electric vehicles and diminished fossil fuel consumption for conventional engines. Moreover, the technology accelerated the time required to achieve a comfortable interior temperature by approximately 17 minutes, enhancing occupant comfort and reducing energy wastage.

Beyond summer benefits, the STRC film was rigorously tested during winter months, where its effects on heating energy demand were analyzed. Intriguingly, while the cooling advantages were pronounced, any increase in heating requirements due to infrared emission was minimal, ensuring year-round net energy savings. This overall efficiency positions the technology as a viable avenue for automotive decarbonization, aligning with global initiatives to reduce greenhouse gas emissions from transport sectors.

To contextualize its environmental impact, simulations based on widespread adoption across the United States estimate an annual reduction of approximately 25.4 million tons of CO2 emissions. This figure corresponds to taking roughly five million vehicles off the road, highlighting the STRC film’s potential contribution to national and global carbon neutrality goals. The convergence of material innovation, automotive engineering, and environmental science embodied in this project underscores the holistic approach required to tackle climate change challenges.

The invention has sparked interest not only in the academic and industrial communities but also in intellectual property domains. A Korean patent application (no. 1020230179087) has been filed by the inventors, securing rights over the STRC film technology. This move positions the research team and their partners strategically for collaborations, licensing deals, and mass production efforts to bring this technology to market.

Commenting on the research, Min Jae Lee, first author affiliated with Seoul National University and the Hyundai-Kia partnership, emphasized the significance of validating the film under real operational conditions, transcending prior studies confined to laboratory-scale evaluations. Professor Seung Hwan Ko echoed this sentiment, marking the work as the first experimental demonstration of transparent radiative cooling viable for practical vehicle environments. Their synergy has propelled the field toward a new era of passive thermal management.

The sophisticated multilayer design, material selection methodologies, and rigorous computational modeling underpinning the STRC film’s development reflect state-of-the-art innovation. This integration of theoretical photonics, nanoscale engineering, and practical automotive requirements typifies contemporary interdisciplinary research. The measured spectral properties, durability under prolonged solar exposure, and compatibility with existing vehicle manufacturing pipelines further attest to the film’s readiness for adoption.

As transportation electrification gains momentum worldwide, innovations like the STRC film that enhance energy efficiency without augmenting complexity or cost herald promising pathways for sustainable mobility. The film’s capacity to function autonomously, without electrical input, aligns with broader trends toward passive technologies in climate control systems, potentially inspiring applications beyond vehicles, in buildings and wearable devices.

Seoul National University, established in 1946 as South Korea’s first national university, exercises critical leadership in engineering research. The college’s commitment to nurturing global industry leaders is exemplified by this successful collaboration, which bridges academia and industry to foster impactful technologies. By pushing the envelope of radiative cooling applications, the research reaffirms the institution’s role in addressing pressing environmental challenges through innovation.

This milestone achievement invites further exploration into scalable manufacturing techniques, integration with diverse vehicle models, and synergy with other energy-saving technologies. The fusion of transparent radiative cooling with smart sensors or adaptive coatings could pioneer next-generation climate-responsive automotive glass, further enhancing passenger comfort and environmental sustainability. As the automotive industry accelerates toward carbon neutrality, solutions like the STRC film will be instrumental in shaping the future of mobility.

Subject of Research: Not applicable

Article Title: Towards decarbonization in transportation: scalable transparent radiative cooling for enhanced vehicle energy efficiency

News Publication Date: 4-Feb-2026

Web References: http://dx.doi.org/10.1039/D5EE06609C

References: Energy & Environmental Science, 2026

Image Credits: © Energy & Environmental Science, originally published in Energy & Environmental Science

Keywords

Transparent radiative cooling, vehicle energy efficiency, passive cooling, multilayer film, near-infrared reflection, mid-infrared emission, sustainable transportation, cabin temperature control, automotive glass, energy-saving technology, carbon reduction, scalable nanomaterials

Radiative cooling serves as a passive thermal management approach that facilitates heat dissipation through the emission of infrared radiation into the surrounding space without consuming external energy. This method contrasts starkly with traditional cooling systems, which often falter in extreme settings such as arid deserts, high-altitude aircraft, or even the vacuum of outer space. The insights presented in this review emphasize the critical importance of precisely engineered micro- and nano-scale materials, which are adept at selectively emitting and reflecting thermal radiation. Thus, they can effectively achieve robust cooling even amidst harsh conditions marked by intense solar radiation, high humidity levels, or even complete vacuum scenarios.

The review systematically categorizes the environmental challenges that necessitate innovative cooling solutions into four primary categories, each representing distinct operational climates. First, in terrestrial dwelling environments, materials must display resistance to ultraviolet radiation, microorganisms, intense heat, and environmental pollutants while simultaneously maintaining high emissivity in the mid-infrared spectrum—specifically within the 8 to 13 micrometer range. One notable breakthrough mentioned is a polyoxymethylene nanotextile that accomplishes a remarkable 95% sunlight reflection while emitting 75.7% infrared radiation in the desired spectrum, all while resisting degradation from UV exposure and physical abrasion.

As we delve deeper into terrestrial extreme environments, such as deserts and tropical regions, the need for cooling systems that perform well under high temperatures and extreme humidity becomes paramount. The researchers highlight innovative solutions involving dual-selective emitters. These not only utilize secondary atmospheric windows measured between 3-5 micrometers and 16-25 micrometers but also coordinate with evaporative cooling techniques and phase change materials (PCMs). This synergistic combination results in enhanced heat dissipation capabilities, allowing these systems to remain efficient and reliable in challenging climatic conditions.

When it comes to aeronautical settings, the need for infrared stealth becomes a vital consideration. Here, materials must strategically emit radiation in non-atmospheric windows—specifically the 5 to 8 micrometer range—while suppressing emissions within the 8 to 13 micrometer range to evade detection by thermal imaging systems. The review introduces multilayer metamaterials and photonic crystals that uniquely serve both purposes, offering a solution that marries infrared camouflage with effective radiative cooling. This dual functionality is not just an exercise in academic innovation; it holds practical applications in advanced aircraft designs and military technologies.

The challenges escalate even further in outer space environments, where materials are subjected to the harsh realities of cosmic radiation, atomic oxygen erosion, and blistering temperatures exceeding 1200 degrees Celsius. In this context, the review addresses the development of new all-inorganic coatings, including phosphate geopolymer paints and silica aerogels. These materials have shown remarkable resilience in maintaining optical performance, even after pronounced exposure to proton irradiation—an essential characteristic for materials intended for long-duration missions in space.

As the authors navigate the potential applications of these advanced materials, they highlight that their relevance extends far beyond academic curiosity. Radiative cooling materials are beginning to find their way into practical implementations such as architectural coatings, personal cooling garments, aircraft exteriors, and thermal shields for spacecraft. This intersection of advanced materials and real-world application underscores the promising future of passive cooling solutions across various industries.

The review also sets forth a forward-looking perspective regarding the future trajectory of radiative cooling technologies. The concepts of multifunctional materials—those incorporating features such as flame retardancy, UV resistance, antimicrobial properties, and even self-cleaning functionalities—are emerging as key areas of focus. This convergence of capabilities not only enhances operational efficiency but also provides added benefits for end-users across diverse applications.

Moreover, the ability to achieve dynamic spectral tuning—to adapt cooling or heating properties based on specific environmental circumstances—has gained significant attention. This adaptability would enable the creation of smart materials that can respond in real time to changing conditions, optimizing their performance and efficiency as required. Similarly, hybrid cooling systems that blend radiative processes with evaporative and latent heat transformation strategies stand poised to revolutionize traditional thermal management systems, heralding a new era of energy-efficient technologies.

In summary, this extensive review serves as an invaluable framework for advancing the design and development of next-generation radiative cooling materials that can excel in extreme environmental conditions. The cohesive blend of materials science, photonics, and thermal engineering championed by the authors lays the groundwork for innovative, passive cooling technologies capable of transforming everything from urban infrastructures to the exploration of outer space. The ongoing research endeavors led by Professors Han Zhou and Di Zhang at Shanghai Jiao Tong University are set to continue shaping the field, promising a future where thermal management is no longer a limiting factor, but rather a reliable and efficient aspect of environmental control.

In conclusion, the relentless march of technological advancement creates a position of urgency for efficient thermal management solutions. Through meticulous research and innovative thinking, the scientists at Shanghai Jiao Tong University are forging pathways that stretch the boundaries of possibility, addressing an essential need that resonates across all sectors of the modern world.

Subject of Research: Radiative cooling materials for extreme environments
Article Title: Radiative Cooling Materials for Extreme Environmental Applications
News Publication Date: 7-Jul-2025
Web References: http://dx.doi.org/10.1007/s40820-025-01835-9
References: Not provided
Image Credits: Jianing Xu, Wei Xie, Hexiang Han, Chengyu Xiao, Jing Li, Yifan Zhang, Shaowen Chen, Binyuan Zhao, Di Zhang, Han Zhou.

Keywords

Radiative cooling, thermal management, extreme environments, innovative materials, Shanghai Jiao Tong University, passive cooling technology, micro- and nano-structured materials.