Diamagnetic levitation with permanent magnets for contactless guiding and trapping of microdroplets and particles in air and liquids

Diamagnetic levitation was applied to micro-positioning and trapping of diamagnetic micron-sized particles and micro-droplets. Scale reduction laws for magnetism indicate that diamagnetism is highly efficient for magnetic MEMS. We demonstrate here that diamagnetic bodies can be contactless guided along magnetic grooves or trapped in magnetic wells both in air and in liquids. Levitation of water, ethanol and oil microdroplets was achieved within a 1.6 mm bore of a cylindrical magnet and in micromachined bulk magnets. Thick permanent micromagnets were also electroplated above silicon wafers in various matrix configurations. Diamagnetic levitation on micromagnet arrays was tested with 3 pm-large diamagnetic latex beads in a paramagnetic buffered solution. Trapping and arraying of microparticles in stable spatial levitation within magnetic wells were successfully achieved.