Design and fabrication of a micromachined multispectral magnetic resonance imaging agent

This paper describes the fabrication details of magnetic nano- and microstructures that enable a new class of multispectral magnetic resonance imaging agents. Magnetic field and associated geometrical fabrication constraints particular to these new multispectral contrast agents are described, and fabrication schemes based on both electrochemical deposition and thermal evaporation are presented. Relative advantages and disadvantages of top-down microfabrication approaches versus traditional bottom-up chemical synthesis routes are discussed with a focus on trade-offs between resulting microparticle functionality and fabrication process economy. It is shown that large numbers of contrast agent nano- or microstructures can be simultaneously fabricated, suggesting that top-down microfabricated contrast agents may represent an economical, attractive alternative to those based on chemically synthesized molecules or nanoparticles.