title: Self-Propelled Nanomotors Autonomously Seek and Repair Cracks.
abstract: Biological self-healing involves the autonomous localization of healing agents at the site of damage. Herein, we design and characterize a synthetic repair system where self-propelled nanomotors autonomously seek and localize at microscopic cracks and thus mimic salient features of biological wound healing. We demonstrate that these chemically powered catalytic nanomotors, composed of conductive Au/Pt spherical Janus particles, can autonomously detect and repair microscopic mechanical defects to restore the electrical conductivity of broken electronic pathways. This repair mechanism capitalizes on energetic wells and obstacles formed by surface cracks, which dramatically alter the nanomotor dynamics and trigger their localization at the defects. By developing models for self-propelled Janus nanomotors on a cracked surface, we simulate the systems' dynamics over a range of particle speeds and densities to verify the process by which the nanomotors autonomously localize and accumulate at the cracks. We take advantage of this localization to demonstrate that the nanomotors can form conductive "patches" to repair scratched electrodes and restore the conductive pathway. Such a nanomotor-based repair system represents an important step toward the realization of biomimetic nanosystems that can autonomously sense and respond to environmental changes, a development that potentially can be expanded to a wide range of applications, from self-healing electronics to targeted drug delivery.
authors.affiliation: Department of Nanoengineering, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States.
authors.forename: Oleg E
authors.initials: OE
authors.lastname: Shklyaev
authors.affiliation: Department of Nanoengineering, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Tianlong
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Nanoengineering, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States.
authors.forename: Henry
authors.initials: H
authors.lastname: Shum
authors.affiliation: Department of Nanoengineering, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Isaac
authors.initials: I
authors.lastname: Rozen
authors.affiliation: Department of Chemical Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States.
authors.forename: Anna C
authors.initials: AC
authors.lastname: Balazs
authors.affiliation: Department of Nanoengineering, University of California San Diego , La Jolla, California 92093, United States.
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang
mesh_terms: D049329:Nanostructures
keywords: Nanomotor; autonomous repair; biomimetic; localization; propulsion