Paper Number
MN5 

Session
Micro and Nanofluidics

Title
Stokes trap: Multiplexed particle trapping and manipulation using precision microfluidics

Presentation Date and Time
October 14, 2015 (Wednesday) 11:40

Track / Room
Track 6 / Frederick/Columbia

Authors (Click on name to view author profile)

1. Schroeder, Charles M. (University of Illinois at Urbana-Champaign, Chemical & Biomolecular Engineering)
2. Shenoy, Anish (University of Illinois at Urbana-Champaign, Chemical & Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Charles M. Schroeder and Anish Shenoy
Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801

Speaker / Presenter 
Schroeder, Charles M.

Text of Abstract
The ability to trap and control single particles in free solution has led to major advances in science and engineering. In this talk, we report the development of the Stokes Trap, which is a multiplexed microfluidic trap for control over an arbitrary number of small particles in a microfluidic device. Our work involves the design and implementation of 'smart' flow-based devices by coupling feedback control with microfluidics, thereby enabling new routes for the fluidic-directed assembly of particles or the development of precise methods for single particle rheology. Here, we discuss the development of a new method to achieve multiplexed microfluidic trapping of an arbitrary number of particles using the sole action of fluid flow. In particular, we use a Hele-Shaw microfluidic cell to generate hydrodynamic forces on particles in a viscous-dominated flow defined by the microdevice geometry and imposed peripheral flow rates. Addition of multiple inlets to the cell increases the degrees of freedom for trapping additional particles. We employ a model-predictive controller for the non-linear system and solve a constrained optimal control problem in real-time. This platform allows for a high degree of flow control over individual particles and can be used (for example) for fluidic-directed assembly by bringing two particles together in time and space. From a broader perspective, our work provides a solid framework for guiding the design of automated on-chip experiments for conducting single particle and single molecule rheology under controlled conditions and environments.