Flexible Solar Modules with Low-Cost Prismatic Encapsulation

This Phase II program will demonstrate an innovative, module-level encapsulation technology that will lower the cost by at least 50% and enhance the performance of space-grade solar arrays. Conventional solar cells for space use specialized coverglass that provides essential environmental protection from high-energy particle and ultraviolet solar radiation but is expensive to apply and has high fragility. Next-generation coverglass replacement materials have been explored by several groups over the past decade. Pseudomorphic glass (PMG) uses glass microbeads embeded in a silicone matrix that can be formed into sheets or sprayed on interconnected modules. Pure silicone sheets using space-grade DC 93-500 have also been investigated for module-level protection. Both approaches have the additional benefit of high flexibility that is synergistic with thin-film, inverted metamorphic multi-junction (IMM) solar cells manufactured by MicroLink Devices, enabling a pathway to truly flexible solar modules. The central innovation in this proposal is to introduce a novel, prismatic texturing method that will improve the performance and manufacturability of silicone-based encapsulations including PMG. Texturing of glass encapsulants has previously been explored for enhancing high-angle light capture for terrestrial solar arrays, but prismatic structuring of space coverglass has not been widely investigated. Polymer materials are much more readily formed into prismatic shapes, which presents a new opportunity to introduce this important technique. During the Phase I program MicroLink demonstrated 4% higher output power as well as enhanced high-angle capture using low-cost prismatic silicone and robust UV rejection (UVR) coatings. This was used to fabricate the first truly flexible, space-grade module with multi-junction solar cells. Deployable, retractable arrays such as the Lunar VSAT would be an excellent application for the new module technology. This Phase II program will demonstrate an innovative, module-level encapsulation technology that will lower the cost and enhance the performance of space-grade solar arrays. Conventional coverglass is expensive to apply and has high fragility. The central innovation is to introduce a novel, prismatic texturing method compatible with next-generation pseudo-morphic glass (PMG) module-level encapsulation. Texturing of glass encapsulants has previously been demonstrated for enhancing high-angle light capture in terrestrial solar arrays but has not been widely explored for space applications. Silicone-based PMG encapsulations can be readily formed into prismatic shapes. Prismatic texturing will improve array output power by 4%, increase the high-angle collection efficiency of space solar cells by up to 30%, reduce the solar array operating temperature by as much as 3 degrees, reduce satellite “flare” and visibility, and substantially simplify the design and robustness of essential UV protective coating layers deposited over the encapsulation. Develop a mass-optimized production prism design which provides similar, excellent optical performance to the Phase I demonstration but scales the prism height to below 50 mm for reduced encapsulation mass. Produce a custom, diamond-turned master mold and carry out a pilot production run of prismatic acrylic sheet, validated by microscope evaluation. Finalize the production UVR coating process, with further optimizations to optical transmission and film stress.  Scale the process to module-sized (>0.3x0.3 m2) deposition with high uniformity and reproducibility. Carry out systematic evaluation of the robustness of UVR-coated prismatic solar modules in space environments, including exposure to vacuum ultraviolet, electron and proton radiation, outgassing, temperature cycling and atomic oxygen exposure. This work will build on a well-established base previously carried out for coated silicone lenses. Develop a pilot production process for manufacturing panel-sized prismatic encapsulation at MicroLink Devices, including automated dispense of silicone-based bonding layers and prism sheet material. Quality controls will be established to monitor prismatic sheet optical performance. Program deliverable: 0.3 m2 prismatic-encapsulated module fabricated using MicroLink’s 3J-IMM solar cells.

Spacecraft, Lunar and Planetary Missions – Lightweight, flexible roll-up power modules for Lunar VSAT. Large-scale SEP (solar electric propulsion) spacecraft with high specific power solar arrays for a variety of NASA science missions. Satellites – The IMM solar modules are low cost and have low mass with high output power and will be beneficial for large-scale deployment of constellation satellites and cubesats.   Unmanned Aerial Vehicles (UAVs) – High-altitude long-endurance (HALE) solar UAVs such as the Airbus Zephyr, which have variable sun incident angles depending on time of day/year and latitude. Commercial Satellites – Flexible “roll-out” arrays, LEO constellation satellites that require low cost and reduced visibility. Textured sheets can be applied to all solar cell technologies.

This is early/mid-stage (TRL 6) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.