Sensing a physical movement with a Ferrofluidic device

In this paper the development of an inertial sensor for vibration measurements based on the use of ferrofluids is presented. The use of ferrofluids as inertial mass offers advantages over traditional devices like robustness against inertial shocks and performances controllable via electrical signals; moreover, ferrofluids density and other physical features can be controlled by an external magnetic field. The device consists of a glass pipe housing a drop of ferrofluid in a water environment. Two membranes are used to seal the glass pipe at its extremities and to transfer the vibration to the ferrofluidic mass. An inductive readout strategy is used to sense imposed vibrations. Simulations of the device behavior and the real prototype are presented along with preliminary experimental results. Key-Words: Ferrofluids, Inertial sensor, robustness, solid-mass free, tunable performances.