SpaceSkin: development of aerospace-grade electronic textile for simultaneous protection and high velocity impact characterization

Abstract

This paper introduces the concept of an aerospace-grade electronic textile and summarizes design studies and early prototype development for on-fabric hypervelocity impact characterization. Whereas most damage detection technologies for aerospace systems rely on enhancements to the structure's inner shell, the outermost protective skin of a space habitat or a spacesuit -traditionally a woven fabric -is directly exposed to the relevant environment. Therefore, we propose weaving sensory fibers into traditional fibrous aerospace skins for direct measurement of local conditions, yielding a material that can simultaneously sense and protect. Specifically, this paper documents design considerations for multifunctional Beta cloth, in which piezoelectric yarn is directly woven into Teflon-coated fiberglass, the material used as the outermost skin of the International Space Station. A review of hypervelocity plasma generation then motivates a strawman design for on-textile plasma charge and RF emission sensing, which may be useful for further characterization of hypervelocity impactors. An aerospacegrade electronic textile is distinct from a traditional e-textile in that it must be validated not only for its sensing capabilities but also for its robustness to hazards presented in a space environment.

Large-area electronic skins in space: vision and preflight characterization for first aerospace piezoelectric e-textile

“…Historically, the term 'smart skin' has been used in an aerospace context in reference to rigid composite laminates. 8 Described here is a piezoelectric Beta cloth fabric prototype -a smart material initially proposed in [3] that can help to protect and sustain a future tourist's space habitat while also aiding scientists by characterizing sub-millimeter impactors. Broadly, it is a cousin to JAXA's CLOTH Smart Multi-Layer Insulation (MLI) concept in which commercial PVDF film is inserted into an inner layer of conventional MLI.…”

“…quartz or due to beta-phase dipole alignment in semicrystalline polymers. We have previously provided a brief introduction to ferroelectrics as derived from Gibbs free energy in [3].…”

“…Method 1: SpaceSkin Coated Fiber The outer rubber shielding and outer copper braiding are removed using precision wire strippers, leaving an inner copper wire core and poled PVDF-TrFE cladding. The * For an initial presentation of the "SpaceSkin" concept, see [3], 2019). Figure 2.…”

“…However, by modifying the fiber's concentric geometry and disordering the beta-aligned crystalline structure when crimping the prepoled active element, the d 33 coefficient is reduced to approximately -9 pC/N. From significant previous prototyping effort as documented [3] and summarized in Table 2, the modification to piezoelectric cable described in Method 1 above is found to be the best available prototyping option short of extruding custom multimaterial fibers with specialized equipment. It is a versatile approach that produces fibers with enough mechanical flexibility and a small enough geometric cross section to be cleanly weft inserted into a textile substrate.…”

“…* To this end, in 2020, we will be launching the first suite of electronic textile samples to the ExHAM external exposure facility on the International Space Station for initial material resilience testing. An emphasis on hypervelocity impact detection (as initially conceptualized in [3]) sets the stage for the breadth of additional possible functions for a sensate textile in space -from pressurized spacesuit skins that detect external touch, to tension-sensing spacecraft tethers.…”