Magneto-Mechanical Resonators

Magneto-mechanical resonators (MMR) are a young sensor concept that we develop at the Chair of Metrology in Rostock. An MMR consists of two permanent magnets: a stator fixed to the housing and a rotor that can turn around its main axis. The magnetic interaction between both magnets creates a restoring torque, so that the rotor performs a damped oscillation after excitation.

Because the resonance frequency depends on the distance between the magnets, a single millimeter- or sub-millimeter-sized component yields the position and full orientation (tracking) as well as a physical quantity (sensing), for example temperature via thermal expansion or pressure via a compressible housing. MMR need neither a power source nor an antenna, work without line of sight and are inexpensive to manufacture.

Our current work concentrates on four directions:

• making the readout devices more sensitive through low-noise signal processing,
• modelling and characterizing the sensors to understand their behaviour and its effect on measurement accuracy,
• solving the inverse problem of orientation and position more precisely,
• developing new excitation approaches for MMR.

Target applications are radiation-free navigation of medical instruments, swallowable and implantable sensors for physiological parameters, and robust measurements in industrial processes such as pressure and temperature in bioreactors.