Description: NanoSonic proposes to design and develop light-weight, low-modulus, and durable Metal Rubber™ sensors for aeroelastic analysis of Hypersonic Decelerator Entry Systems (HDES), which would in effect increase the systems aerodynamic stability by contributing to optimize its design. The in-situ Metal Rubber™ (MR™) strain sensors would be utilized to monitor drag at varying Mach flow regimes (subsonic to hypersonic) by analyzing dynamic pressures, and billowing effects (or similar shape-change / inflation effects) of the inflatable system as it goes through simulated re-entry flow regimes in wind tunnel tests and in-flight. The novel MR™ sensors have proven the ability to monitor aerodynamic events, particularly shear and normal forces, based on their response to applied strain. These previous sensor technological advancements will be modified to develop the proposed sensor system for monitoring dynamic loading of HDES. Because commercial strain gauges are not capable of withstanding such high strain levels, and photogrammetric analysis can be cumbersome and is not possible in all wind tunnel tests or in-flight analyses, MR™ sensors are ideal for the proposed application. Lightweight MR™ sensor appliqu¿s can be attached onto HDES materials, integrated in or under the system coating matrix for in-situ non-invasive and even wireless monitoring.

Benefits: The proposed SBIR program would develop an innovative, light-weight, low-modulus, and durable Metal Rubber™ sensor system for NASA's hypersonic decelerator entry systems. Some possible other applications for similar Metal Rubber™ materials for other NASA platforms (particularly aerospace systems) include: low-modulus strain and skin friction sensors for adaptive / morphing aircraft systems, hypersonic sensors for other inflatable re-entry systems, low-modulus materials or conformal coatings for EMI shielding, and flexible electrically-conductive wires.

There is a large market for low-weight high strain sensors for scientific balloons, high altitude morphing systems, and similar re-entry inflatable systems, specifically for NASA and the aircraft industry. NanoSonic's low modulus Metal Rubber™ sensor plies and multi-element sensor arrays have unique applications in systems where strain is large and conventional stress and strain sensors mechanically fail. Because Metal Rubber™ is extremely durable, low modulus, and can have high electrical conductivity; it can also be used in high performance, highly flexible and mechanically robust electronic flex circuits, flexible displays and smart electronic fabrics, and as a replacement for conventional lead-based solder.