title: Targeted Self-Healing by Magnetically Guiding Microcapsules.
abstract: Magnetically guided microcapsules are used to achieve self-healing with 1/10th of the healing components required using traditional self-healing approaches. Microcapsules are rendered responsive to magnetic fields by suspending magnetic nanoparticles in the core material. The nanoparticles are surface-modified to enable urea-formaldehyde encapsulation within a phenyl acetate core. Magnetic fields are used to guide the microcapsules to the expected fracture location in tapered double-cantilever beam (TDCB) epoxy specimens. This guiding method achieves an order of magnitude increase in local microcapsule concentration over controls, resulting in successful self-healing at microcapsule concentrations as low as 0.025 wt %. Additionally, the observed healing is both more consistent and significantly higher than that of control specimens, remaining relatively constant across all weight percentages tested.
authors.affiliation: Department of Mechanical Engineering, The University of Tulsa , 800 S. Tucker Dr., Tulsa, Oklahoma 74104, United States.
authors.forename: Matthew D
authors.identifier: http://orcid.org/0000-0002-3031-1446
authors.initials: MD
authors.lastname: Crall
authors.affiliation: Department of Mechanical Engineering, The University of Tulsa , 800 S. Tucker Dr., Tulsa, Oklahoma 74104, United States.
authors.forename: Michael W
authors.identifier: http://orcid.org/0000-0002-4668-7691
authors.initials: MW
authors.lastname: Keller
keywords: guided placement; magnetic nanoparticles; microencapsulation; polymeric materials; self-healing; targeted location