Magnetically-Controlled Microfluidic Devices and Structures

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The goal of this Engineering Microsystems: "XYZ" on a Chip project is to investigate magnetic colloidal particles and their use in several micro-fluid mechanics applications. The need to miniaturize and perform parallel chemical and biochemical processes for efficient drug screening, chemical detection, and combinatorial chemistry motivates interest in chemical processes on a microscopic scale. Most of the current state of the art relies on pressure-driven and electrokinetic processes to transport analytes and products around device. In this work another control parameter, a magnetic field, is added to the system. The self-assembly of magnetic colloidal particles into chains is the key process. When tethered to surfaces in microscopic fluid flow and suspended analytes. The microscopic flow system, chemically patterning the surfaces, and linking the magnetic chains to surfaces will be designed, and then studying the resulting fluid mechanics and magnetic chain dynamics will be investigated. The fundamental issues to be addressed include: the dynamics and mechanical properties of tethered and untethered chains of magnetic colloidal particles; the microscopic fluid mechanics; the filtering and sieving capabilities of magnetic bead arrays; and the micro-scale mixing performance of actuated micromagnetic stirrers. Examples are presented for separation processes involving sieving or filtration of cells or particles, and the converse issue of effective mixing in a microreactor. This project will be conducted in collaboration with the Stanford Nanofabrication Facility, a part of the NSF National Nanofabrication Users Network.