Softgoods Webbing Integrated Strain Sensor for Inflatable

This SBIR project focuses on design, fabrication, and testing of textile based strain sensors to measure the health of structural softgoods elements. In Phase I Paragon iterated through dozens of sensor configurations and down-selected to a single embroidered configuration with exceptional linear and cyclical trends. The Phase II effort will include further iteration of the down-selected design configuration to optimize for repeatability and manufacturability. Iteration and testing will utilize a dead-weight system to inform further configurations and include long duration testing of at least 1 month. Phase II will integrate conductive traces directly into the webbing to minimize wiring needed across a structure. The SWISS Phase II effort will develop a software and electronics interface to multiplex an array of sensors, giving simple usable data output. Paragon will design and build a subscale inflatable test article, deploy the SWISS sensors on the article, and test/evaluate the system in a relevant environment of plain-woven restraint lines under constant load over a multi-week evaluation. The culminating test will utilize optical tracking to evaluate the sensor performance. Deliverables will include the actual test article for NASA evaluation and a single-strand sensor, as well as the detailed reports therein. NASA and commercial companies have demonstrated a continued interest in inflatable habitats for both Low Earth Orbit (LEO) and Lunar Exploration. Initially developed as part of the NASA TransHab program, and eventually built and flown by Bigelow Aerospace, inflatable habitats are becoming a common theme in future exploration plans. Inflatable structures offer the potential for creating large-scale shirtsleeve environments for crew habitation, stowage, and science applications outside the confines of rocket fairings. Additionally, softgoods inflatables are being increasingly used for other important space applications, such as landing bags, parachutes, and re-entry shields, where similar strain gauges would be highly applicable Paragon Space Development Corporation (Paragon) has developed a novel and precise embroidery patterned resistive strain gauge into the webbing itself, which alleviates the problems of adhesion and creep hysteresis. Objective 1: Release of a requirements document validated by the customer. Objective 2: Complete long duration cyclic and time-based testing using a dead-weight system. Objective 3: Downselect Sensor architecture based on testing. Objective 4: Optimize sensor configuration for manufacturing and durability. Objective 5: Array Architecture: release document outlining design of multiplexing, circuits, and telemetry. Objective 6: Development and delivery of a “Common Trace” webbing architecture. Objective 7: Analyze sensor performance in relevant environment (vacuum). Objective 8: Design and fabricate a subscale inflatable habitat. Objective 9: Test sensor system in-situ with a subscale inflatable habitat. Deliverables: At the completion of year 1, a 1-meter length of Vectran with an integrated strain sensor will be delivered to NASA for evaluation. The single-axis length of webbing will include ground and signal leads that can interface with standard multimeter equipment to evaluate the sensor performance and reproduce Paragon results. At the culmination of the Phase II, Paragon will deliver the entire subscale inflatable habitat with an array of integrated strain sensors deployed across the system. The inflatable deliverable will include pressure plugs and interfaces, as well as the back-end software and hardware necessary to output sensor readings without a multimeter.
Benefits: Space industry applications include inflatable structures, space suits, robotic systems, and crew and cargo restraint systems. Inflatable habitats: NASA and commercial companies are working towards “Lunar permanence” and increased inhabited space habitats in the next decade. This entails significant development and deployment of inflatable structures in space and on the moon, for example. Paragon’s SWISS technology is well positioned to play a critical role in ensuring the safety of these habitats.. Our technology could make a large impact in a host of applications including the lifting and rigging industry, high-altitude balloons, safety harnesses, parachutes, machinery/bulk transport, and even automobile seatbelts. This proposal goes into greater detail regarding the size of market, the potential for each application and the path forward.