Biomedical subjects

Gary Friedman

Publications and source records attributed to Gary Friedman.

3 recordsLinked to original sources

PubMed2005

Arranging matter by magnetic nanoparticle assemblers.

We introduce a method for transporting colloidal particles, large molecules, cells, and other materials across surfaces and for assembling them into highly regular patterns. In this method, nonmagnetic materials are manipulated by a fluid dispersion of magnetic nanoparticles. Manipulation of materials is guided by a program of magnetic information stored in a substrate. Dynamic control over the motion of nonmagnetic particles can be achieved by reprogramming the substrate magnetization on the fly. The 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.

Journal Article↗

PubMed2005

Carbon nanotubes loaded with magnetic particles.

We describe a simple and versatile technique to produce magnetic tubes by filling carbon nanotubes (CNTs) with paramagnetic iron oxide particles ( approximately 10 nm diameter). Commercial ferrofluids were used to fill CNTs with an average outer diameter of 300 nm made via chemical vapor deposition into alumina membranes. Transmission electron microscopy study shows a high density of particles inside the CNT. Experiments using external magnetic fields demonstrate that almost 100% of the nanotubes become magnetic and can be easily manipulated in magnetic field. These one-dimensional magnetic nanostructures can find numerous applications in nanotechnology, memory devices, optical transducers for wearable electronics, and in medicine.

Colloids↗

PubMed2004

Programmable assembly of colloidal particles using magnetic microwell templates.

A substrate of thin micromagnets covered by a template of microwells is used to direct the assembly of superparamagnetic colloidal beads into two-dimensional arrays. It is confirmed that the magnetization of the micromagnets can direct beads to programmed locations on the substrate with assistance of externally applied magnetic fields. Empirical investigations on this topic were guided by mathematical models with the intent to elucidate the conditions that promote a single bead to be assembled in the desired microwells. To demonstrate that this technique is programmable, heterogeneous arrays of colored beads are produced.

Colloids↗