Optically Interrogated Thin Film Strain Gauge for Balloon

To support development of atmospheric balloons and gossamer structures, NASA requires a capability for real-time, dynamic strain measurement in thin polymeric membranes during deployment and flight. This capability will provide quantitative test data to inform balloon design efforts, as well as enable real-time monitoring of material state during flight. Existing technologies include wired or wireless electrical or fiber-optic strain gauges, impractical to implement on a thin membrane; photogrammetric techniques that require multiple cameras, detailed knowledge of nominal balloon geometry, and significant post-processing computation; and exotic optical techniques that are unsuited for large scale, dynamic balloon testing and flight. We will develop a completely novel measurement system based on an optically-interrogated thin-film elastomer strain gauge that will provide sensitive, real-time, two-component strain measurement in balloon gores. A large number of the low modulus, thin-film sensors distributed across the balloon will be interrogated remotely at high frequency with a single camera that can be mounted on the payload.