Magnetic Levitation in Chemistry, Materials Science, and Biochemistry

: All matter has density. The uses of density to characterize matter date back as early as ~250 BC when Archimedes was believed to have solved "The Puzzle of The King's Crown". Today, measurements of density are used to separate and characterize a range of materials, and their chemical and/or physical changes in time and space. This review describes a density-based technique-Magnetic Levitation (here called "MagLev")-developed and used to solve problems in the fields of chemistry, materials science, and biochemistry. MagLev has two principal characteristics-simplicity, and applicability to a wide range of materials-that make it useful for a number of applications (for example, characterization of materials, quality control of manufactured parts, self-assembly of objects in 3D, separation of different types of biological cells, bioanalyses, and many others). Its simplicity and breadth of applications also enable its use in low-resource settings (for example, in evaluating water/food quality, identifying counterfeit drugs, and diagnosing diseases).