Robust Lightweight CNT Wiring for Space Systems

NASA is challenged to find ways of effectively shielding sensitive electronic equipment from electromagnetic interference (EMI) without adding significant weight to space flight vehicles and satellites (the heavier they are the more fuel they need to achieve orbit). EMI shielding for wire and cables is an attractive opportunity for weight reduction. However, with the advent of highly reusable next generation space vehicles, wiring must be not only light weight, but also strong and robust, capable of withstanding extreme conditions, intense vibration and long lifecycles. It is important that wire weight reductions do not come at the expense of mechanical strength or EMI shielding effectiveness. DexMat is developing a novel and highly conductive Carbon nanotube (CNT) EMI shield product that will allow for significant weight reduction without compromising mechanical strength or shield effectiveness. CNTs are advancing as the most promising solution for reducing the weight of spacecraft wires. The shielding effectiveness of CNT materials is comparable to that of heavy metal braids, but at a fraction of the weight. Compared to a copper wire with the same diameter, a CNT fiber has 6 times higher strength, more than 6 times lower density, and at least 25 times higher flexure tolerance, essential qualities for conductors in aerospace applications. Under this Phase I project, DexMat will develop CNT shielding braid (made from CNT yarn from Dexmat) that can potentially increase the mechanical strength of CNT tape used as a primary EMI shield. These CNT braids will be of different thicknesses and area coverage, to augment the performance and product appeal of CNT tapes. Additionally, DexMat will begin to conduct the first accelerated aging tests to determine the impact on mechanical strength of shielding made with CNT tapes, CNT yard braids, and hybrid CNT tape/braid combinations.