Simultaneous magnetic and electrostatic driving of microcantilevers

This paper shows that magnetic driving of cantilevers can be accompanied by a simultaneous, out-of-phase, electrical driving. As frequency increases, the increasing voltages on the solenoid not shielded properly enhance electrostatic forces acting on cantilevers placed in its neighbourhood. These forces drive efficiently cantilevers in air and also those immersed in water, although dielectric relaxations in the liquid reflecting its ability to react against the varying electric field, affect this later driving. This electrostatic contamination of the main driving (magnetic) degrades performances of feedback loops built around cantilevers, but it gives a simple reason for the high effectiveness of magnetic driving setups to excite high-frequency vibration modes in micromechanical cantilevers.