Magnet-assisted relocatable functional layers for inflatable structures

Magnet-assisted damage-detecting and self-healing layers for inflatable structures were developed in combination with an instantly cross-linkable material. Covering the outer membrane of inflatable parts from the both sides, the magnet-assisted functional layers are capable of selectively and effectively protecting vulnerable areas, detecting damage with pigmented solution, and repairing the damaged area with cross-linked hydrogel formed from polyacrylic acid (PAA) and calcium chloride. The shear strength, compressive strength, and tensile strength measurement data were analyzed to evaluate the mechanical properties of the resultant hydrogels, and some of which were treated at varied temperatures to clarify temperature dependence. An X-ray diffractometry (XRD) analysis revealed the chemical reaction leading to an ionic bonding between calcium chloride and PAA. A series of damage-detecting and self-healing experiments using a thin film and a blower-powered inflatable structure demonstrated the proper activation of the protective mechanism. Lattice-structured layers realized with a laser cutting machine showed the possibility of being adapted to existing large-scale inflatable structures. These relocatable and disposable damage-detecting and self-healing layers are believed to extend the applicability of protective measures to various inflatable parts as well as to promote related studies and industries.