Arraying nonmagnetic colloids by magnetic nanoparticle assemblers

IEEE Transactions On Magnetics, 42(10): pp. 3548-3553.We review our recent work on the manipulation and assembly of nonmagnetic colloidal materials above magnetically programmable surface templates. The nonmagnetic materials are manipulated by a fluid dispersion of magnetic nanoparticles, known as ferrofluid. Particle motion is guided by a program of magnetic information stored in a substrate in the form of a lithographically patterned template of micromagnets. We show how dynamic control over the motion of nonmagnetic particles can be accomplished by applying rotating external magnetic field. This unexpectedly large degree of control over particle motion can be used to manipulate large ensembles of particles in parallel, potentially with local control over particle trajectory

Improving the efficacy of cellular therapy by magnetic cell targeting

Poster presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/Poster_Presentations/Barbee.pdf.The hot topic of stem cell research has raised hopes for new treatments for a breadth of ailments. As the expectations continue to mount, most related engineering research has been focused around new tools for isolation and propagation of cell lines, with inadequate attention to effective delivery strategies. Invasive or systemic injections come with increased risk and poor efficiency, often wasting a vast majority of the total cellular dosage. We present a method for magnetic targeting of cells in the body with the use of a two-source method of magnetic drug delivery proposed previously in the literature

Magnetically programmable transport and assembly of colloidal particles

This thesis describes the development of tools and methods for enhancing micro-assembly technologies by adding a new means for micro-controlling objects suspended in fluid. Arrays of micro-controllers are formed in thin magnetic film through magnetization patterning, which is often employed in data storage applications. The patterned magnetic film is used in combination with externally applied magnetic fields to manipulate colloidal species in fluids. The micro-controllers have the ability to array particles into chosen patterns on a surface, temporarily or permanently, and the ability to create micro-circulation in the surrounding fluid for transporting, concentrating and sorting colloidal objects. Moreover, the magnetic micro-controllers are capable of being programmed, using traditional magnetic recording methods, to attract or repel objects from particular sites on a surface. Explanations and experimental demonstrations of magnetically programmable assembly processes will be provided in the following chapters, along with a discussion of potential applications.Ph.D., Electrical Engineering -- Drexel University, 200