Shear Thickening Fluids (STF) - Enhanced Textiles for Impact Energy Dissipation, Year 1

The rheological behavior of some liquids can lead to the creation of materials with very unique properties. Shear thickening fluids (STFs), also known as dilatants, are non-Newtonian fluids that stress and shear rates, unlike ordinary liquids where the viscosity decreases with increasing shear rate. One well-known example of an STF is the cornstarch and water experiment, in which the solid-liquid mixture readily flows under low shear; however, when the same mixture is rapidly stirred or struck, it hardens almost instantaneously, resembling a solid. Modern STFs are made from ceramic nanoparticles that are heavily loaded in a carrier liquid. When the shear rate is increased, hydroclusters will form because of collisions with other neighboring nanoparticles and produce a rapid rise in viscosity. The nanoparticles will even lock together and harden when rapidly struck if the shear rate is high enough. When the stress is removed or if the shear rate decreases, the material returns back to its original fluid-like state. In the past decade, STFs made from silica nanoparticles loaded in carrier fluids, such as polyethylene glycol, and impregnated in a fabric have gained attention by the military and law enforcement to have potential for use in liquid body armor [1] and bulletproof vests. More recent interest in STFs include investigating the use of these materials as a layer in spacesuits to provide protection against micrometeoroid orbital debris (MMOD) [2]. Application of STFs impregnated in fabrics for spacesuits could make these materials a promising candidate as a multi-functional deep-space or lunar habitat shell for MMOD protection. The goal is to determine if Shear Thickening Fluids (STFs) embedded in textiles can be used for a lightweight habitat shell to provide effective protection against micrometeoroid orbital debris (MMOD) in a deep-space environment. More »