(278b) Model Predictive Control for Multiplexed Microfluidic Particle Manipulation

A major challenge in nanoparticle design and fabrication is the ability to build complex structures in controlled and directed processes. In the past, self-assembly of particles has been pursued to generate 2D and 3D ordered structures of nanoparticles and colloids; however, development of new methods for the controlled fluidic-directed assembly of anisotropic and/or highly ordered structures would enable new routes for the manufacturing of advanced materials. In this work, we report a fundamentally new technology that will allow for multiplexed particle trapping and directed assembly of small particles using a combination of microfluidics and feedback control. We used nonlinear model-predictive control to manipulate an arbitrary number of small particles in arbitrary directions using microfluidic-based control. In particular, we utilize a Hele-Shaw microfluidic cell to generate hydrodynamic forces on particles under viscous-dominated flow conditions, and we model the flow field inside the microfluidic device as a function of the device geometry and flow rates at the periphery of the cell. In this talk, we will discuss the numerical formulation of this flow model along with the solution of the associated constrained optimal control problem and its implementation as a feedback controller. Finally, we will discuss the experimental implementation of the multiplexed microfluidic trap.