SBIR Phase II:Passive Cooling Materials for Transparent Applications in Refrigerated Trucking and Solar

This Small Business Innovation Research (SBIR) Phase II project seeks to produce and validate the company’s passive cooling thin films to meet specific market requirements such as for refrigerated trailer, inverter, and solar photovoltaic (PV) applications. The product platform may meet the needs of myriad applications and use cases through the development and validation of both transparent and highly reflective/opaque films. The proposed effort may advance the goal of improving cooling technologies by enabling customers in the refrigerated trucking, solar energy, home cooling, and other markets to reduce their greenhouse gas emissions while reducing costs. Examining the annualized refrigerated trucking industry alone, which is valued at $1 billion globally, could reduce greenhouse gas emissions by more than 15 million metric tons of carbon dioxide (CO2) equivalent per year in the U.S.. In addition, application to solar inverters and PV cells may increase the efficiency of renewable power generation. These uses collectively serve to improve the sustainability of multiple industries, with a long-term impact of offsetting the use of fossil fuels and the negative environmental, societal, and health effects tied to them.The intellectual merit of this project is based on exploitation of selective photonic emitters that allow certain wavelengths of light to be emitted above the atmosphere, allowing passive cooling of more than 12.5 degrees C (100 W/m2), with zero energy input and no waste heat generation. Given that the passive cooling is inherent in the microstructure of the film and there is no need for electrical continuity, the product may provide seamless cooling capabilities, even in the unlikely event of mechanical failure of the film. Optimization of the thin films for application-specific use requires the successful completion of three objectives, which are the focus of the Phase II project: 1) investigation of fabrication techniques driving improved film performance compatible with the needs of key market applications, 2) development of application-specific installation methods while maintaining high performance requirements, and 3) development of improved manufacturing processes for production scale-up. Successful accomplishment of these objectives will prime the technology for market entry in a variety of applications, whether new or retrofitted. From a technical perspective, the research and development activities may advance the knowledge of passive radiative cooling systems and how they may be applied to support sustainable innovations in temperature control.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.