SBIR Phase I: Manufacturing USA: Ultra-thin radiative-cooling fabric

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is twofold. (1) Capturing business opportunities in the athleisure market by providing functional textiles with radiative cooling capabilities. As climate change has led to more hot summer days, clothing with advanced cooling features will have significant public safety values. The global cooling fabrics market is projected to grow at a 10% annual rate from $1.8 Billion to $2.9 Billion by 2021. Cooling fabrics conventionally rely upon sweat wicking, and no major brand has incorporated radiative cooling technologies in textiles. MetaRE fabrics will address this unmet need by delivering a novel cooling technology substantially more efficient than sweat wicking. (2) Alleviating the environmental impact of the textile industry. Each year, 63 million tons of synthetic fibers are produced. These fibers turn into 300 billion square meters of textiles, which go through the clothing value chain, and ultimately turn into textile waste. This vast and growing stream of textile waste is creating a massive environmental burden. By introducing nanoscale air voids into fibers, MetaRE fabrics will reduce the consumption of petrochemicals by 30% and will use 50% less dye to reach desired color brightness and saturation. This Small Business Innovation Research (SBIR) Phase I project will establish design and manufacturing technologies for creating radiative cooling fibers and fabrics. The prototype polymer fabrics will have three unique features: superior opacity, radiative cooling, and brilliant metallic luster, all resulting from nanoscale air filaments embedded in the fibers. The radiative cooling feature, in particular, is due to a combination of strong and broadband reflectivity of the fiber in the solar spectrum and high emissivity of the fiber in the thermal radiation spectrum. Research objectives of this SBIR Phase I project include: Develop melt and wet extrusion recipes to produce nanostructured polymer fibers with proper morphology, optical and thermodynamic properties, and mechanical strength; Demonstrate optical, thermodynamic, and mechanical performance of radiative cooling fabrics. To overcome obstacles to industrial adoption, the fiber production processes will require relatively minor changes to existing fiber extrusion equipment, and fibers produced will need to meet mechanical and throughput requirements comparable to those for conventional fibers. A set of optical and thermodynamic techniques and tools will be developed to characterize the spectral properties of the fibers and fabrics from the ultraviolet to the long-wavelength mid-infrared and to quantify the radiative cooling capabilities of the finished fabrics. 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.