Using Nanoparticle-Filled Microcapsules for Site-Specific Healing of Damaged Substrates: Creating a “Repair-and-Go” System

Abstract

Using a hybrid computational approach, we simulate the behavior of nanoparticle-filled microcapsules that are propelled by an imposed shear to move over a substrate, which encompasses a microscopic crack. When the microcapsules become localized in the crack, the nanoparticles can penetrate the capsule's shell to bind to and fill the damaged region. Initially focusing on a simple shear flow, we isolate conditions where the microcapsules become arrested in the cracks and those where the capsules enter the cracks for a finite time but are driven to leave this region by the imposed flow. We also characterize the particle deposition process for these two scenarios, showing that the deposition is greater for the arrested capsules. We then determine the effect of utilizing a pulsatile shear flow and show that this flow field can lead to an effective "repair-and-go" system where the microcarriers not only deliver a high volume fraction of particles into the crack but also leave the fissure and, thus, can potentially repair additional damage within the system.

Modeling crawling cell movement on soft engineered substrates

“…We would also like to note that for such complex deformable and moving geometries as crawling cells or other so self-propelled objects, the phase-eld description presented here has signicant advantages in terms of reducing the computational effort 14 compared to direct simulations. 13 …”

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“…Ca=10 -1 Figure 16 Graphical image of the simulation that shows the movement of a capsule to a microcrack from its initial position (A) to the crack (B), its motion further away from the crack (C), and the release of the nanoparticles (reprinted with permission from [84] the reaction of metallic surfaces with the surrounding material. For this purpose, a surface layer can protect the metal and save it from harmful effects of the atmosphere.…”