Nanocomposite fabric sensors for monitoring inflatable and deployable space structures

Inflatable deployable structures are practical and promising candidates for serving various aerospace missions, for instance, as solar sails, antennas, space suits, and especially Lunar and Mars habitats. These structures feature flexible composites folded at high packing efficiency, which can drastically reduce launch costs. However, they can also be damaged due to the harsh extraterrestrial operating conditions, which can propagate to cause catastrophic mission failure and endanger crew safety. Therefore, it is imperative to integrate a robust structural health monitoring (SHM) system, so that damage and faults can be detected for ensuring their safe and reliable operations. While a variety of SHM technologies have been developed for monitoring conventional, rigid, structural systems, they are faced with challenges when used for these unconventional flexible and inflatable systems. Therefore, a flexible carbon nanotube-fabric nanocomposite sensor is proposed in this study for monitoring the integrity of inflatable space structures. In particular, CNT-based thin films were fabricated by spraying and then integrated with flexible fabric to form the lightweight sensor. By coupling fabric sensors with an electrical impedance tomography (EIT) algorithm, the fabric's distribution of spatial resistivity can be mapped using only electrical measurements obtained along the material's boundaries. The severity and location of localized pressure and impact damage can be captured by observing changes in the EIT-calculated resistivity maps. They can be embedded in inflatable habitat structures to detect and locate abnormally high pressure regions and impact damage.