Designing a Dynamic Platform that Provides Multiple Defense Mechanisms against Fouling
Abstract
In the last year, we designed a hybrid surface that involved a thermo-responsive gel andrigid posts, and showed that this surface provided two distinct mechanisms for repelling isolated,adhesive particles. In the next two years, we will expand our models to encompass multiple,interacting particles, which can adhere to each other, as well as to the surface. Hence, we willdevelop complementary methods to capture the range of phenomena, length scales, and timescales that characterize the behavior of these multi-component systems. In particular, we willexpand our computational approaches to encompass the following:1. Interactions among the algae to form the biofilm2. Interaction of the biofilm with the new multi-functional platform3. Light-responsive gels and magnetically actuated posts (fins)By introducing the first two sets of modifications into our models, we can now determine theoptimal conditions for preventing the adsorption of the particles even before they aggregate intothe biofilm and isolate effective conditions for expelling entire colonies. Through the third set ofmodifications, we will both guide the development of the new multi-functional coatings, andprovide useful predictions to maximize the effectiveness of the system.To achieve these ambitious goals, we will build on our expertise in multi-scale modelingof dynamic interactions in complex fluids. In particular, we will extend our dissipative particledynamics (DPD) simulations1,4 to include multiple algae particles (see Fig. 7) that can bind toeach other and to the surface. The DPD constitutes a particularly powerful approach for thesestudies since the method accurately captures the hydrodynamic interactions in the system.5-7Moreover, we can focus on the nanoscale phenomena occurring in the system and thus, ~zoomin~ to visualize how the rupture of ~sticky~ bonds is affected by changes in experimentalconditions (e.g., shear rate) or features of the coating, such as the actuation of the fins.We will also utilize our more coarse-grained ~LBM/LSM~ technique 8-13 that we recentlyadapted to model the binding of biological cells to compliant surfaces.14 The latter techniquecombines the lattice Boltzmann method (LBM) for fluid dynamics with the lattice spring model(LSM) for the micromechanics of soft particles, i.e., the algae. The LBM/LSM will allow us to6focus on micron scale phenomena occurring in the system as the algae attempt to bind to eachother and chemically and/or physically patterned surfaces.By using these different methods, we can probe phenomena on both the nanoscale (viathe DPD simulations) and microscale (via the LBM/LSM). Furthermore, the DPD simulationsallow us to validate assumptions we make about the bonding interactions in the more coarsegrainedLBM/LSM and facilitate refinements of the latter model. Moreover, by using distinctapproaches to validate our findings, we can show that the results are robust and not modeldependent.Below, we provide a basic description of our different approaches, highlightingaspects of the models that are particularly useful for these studies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141613111
Entities
People
- Anna C. Balazs
Organizations
- Office of Naval Research
- United States Navy
- University of Pittsburgh