Low-Weight, Durable, and Low-Cost Metal Rubber Sensor System for Ultra Long Duration Scientific Balloons

NanoSonic proposes to develop an innovative, low-cost, ultra low mass density, and non-intrusive sensor system for ultra long duration balloons (ULDB) that will operate in the most extreme environmental conditions. Specifically, the sensors would be integrated onto the load bearing seams and/or outer balloon mesh polyethylene surface of the pressurized balloon system to accurately and continually measure axial loads. Large axial load forces and extreme temperature ranges are typical for scientific balloon missions; therefore a durable, flexible, and thermally stable sensor material is needed. NanoSonic would use its highly flexible, low-modulus Metal Rubber<SUP>TM</SUP> (MR<SUP>TM</SUP>) materials as strain/pressure sensors that are capable of large cyclic deformation without failure. MR<SUP>TM</SUP> is a free-standing nanocomposite material produced by the layer-by-layer combination of high performance polymers and electrically-conducting metal nanoparticles that provide durability and recoverability for sensor transduction, and a wide thermal operation range. Importantly, MR<SUP>TM</SUP> can behave like a rubber band in that it can be folded / compressed for stowage and then can be deployed and continually pressurized without failure. Also, because of the very low amount of metallic nanoclusters in the system (<0.02 volume %), the sensor system is extremely low-weight and would not alter the performance of the balloon.