SBIR Phase II: Roll-to-Roll Manufacturing of Highly Crystalline Thin Film Semiconductor Substrates for Flexible Electronics

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project will help enable the expansion of the Internet-of-Things (IoT) through new peel-and-stick sensor nodes. Such IoT nodes require low device cost, and thus low sub-component costs for sensing elements, processing circuits, communications, and power. In addition, they are power constrained, requiring minimal energy consumption during sensor data collection, processing, and transmission. Integrating low-cost and low-power components into a single size-limited device becomes a substantial challenge using conventional semiconductor fabrication materials and processes. This SBIR Phase II project will use a novel System-on-Foil approach that patterns efficient silicon circuitry directly into a novel flexible silicon substrate, alongside low-cost printed electronics. This approach enables the integration of all core IoT elements, including microprocessors, sensors, antennas, interconnects, and power supplies, making robust systems with applications in condition monitoring for civil infrastructure, human health monitoring, automotive, grid battery management, wind turbines, aerospace, and industrial equipment. This Small Business Innovation Research (SBIR) Phase II project will advance a novel semiconductor recrystallization technology to support a new generation of flexible electronics. To include on-board processing, communication, and memory circuitry, current state-of-the-art flexible electronics rely on surface mounting and soldering of off-the-shelf silicon chips, similar to rigid printed circuit board assemblies. This pick-and-place approach not only reduces device flexibility, but also leads to interconnection challenges that severely compromise device reliability. This project leverages a thin film recrystallization process where equivalent silicon circuits can now be patterned directly into flexible silicon, resulting in a highly scalable manufacturing process that drastically improves device reliability. By patterning all components directly into a high-temperature substrate, conformal electronics can be made that are durable even in heavy vibration and shock environments. The project objectives include the transition of prototype recrystallization processes to a higher throughput and higher quality pilot-scale recrystallization system. The resulting flexible silicon substrates will then be used for preliminary development of integrated circuit fabrication to produce active silicon components as a step toward fully patterned System-on-Foil electronics. 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.