The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is in enabling additional energy savings in buildings by harvesting natural daylight and using it for illuminating the interior space with high efficiency and without glare, thus offsetting the need for electrical lighting. This will make building operations more sustainable and help improve the energy security of the U.S, create jobs, and reduce greenhouse gas emissions. Additionally, when commercially available, this new technology will bring all of the well-known benefits of enhanced natural lighting for occupants of millions of residential and commercial buildings across the U.S., such as connection to outdoors and improved comfort, productivity and well-being, thus benefiting many groups of consumers.The proposed project will demonstrate the feasibility of a novel, non-prismatic optical film material and its use for enhanced daylighting harvesting in buildings. This material employs thousands of microscopic reflective surfaces embedded into the bulk of the material and operates by capturing the incident sunlight and projecting it deep into the building interior. Commercial buildings alone consume about 20 percent of all energy used in the United States at an estimated cost of nearly $180 billion. Building interior lighting accounts for around 30% of that cost. By applying the daylight-harvesting optical material to windows of building facades, a significant fraction of that energy consumption can be offset using the natural light captured throughout the day. The project will provide the critical design, testing, and experimental validation needed to transition the technology into the commercial sector. The primary objective of the project is to develop the core light-redirecting material and associated micro-optical fabrication technology that can be subsequently scaled for low-cost mass production. A second objective is to develop, test and demonstrate a prototype daylight-harvesting window film product based on this material.