Diamagnetic Levitation of Solids at Microscale
Résumé
Friction and stiction problems often occur in microsensors and microactuators. An original solution proposed here consists in diamagnetic levitation above integrated micromagnets. This static, energy free, room temperature levitation is seldom used because of the weakness of the forces involved. The scale reduction laws are favorable to these forces. Micrometer scale structures are perfectly suited to this kind of levitation. Both static and dynamic simulations are conducted to predict the behavior of diamagnetic particles above a permanent magnets structure. The static simulations enable one to find the location and to quantify the stability of levitation. Dynamic simulations are required to fully explain the results of the experiments proposed. The structure is then fabricated and successful levitation of bismuth in air and copper and silicon in paramagnetic water is reported. Applications in material conveyance, inertial sensors such as inclinometer or accelerometer are explored.