An in-plane cobalt-nickel microresonator sensor with magnetic actuation and readout

We present magnetic microresonators that utilize magnetic actuation and readout for use as mass sensors. A magnetic readout method was developed for the detection of microresonator vibration. Together with wireless actuation, the wireless magnetic readout results in completely passive microresonators. The magnetic readout is based on the induced voltage on a pair of differential pick-up coils, which is generated by the movement of the magnetized microresonator. The successful operation of the readout was demonstrated with CoNi microresonators under atmospheric pressure and in water. The microresonator can be readily functionalized and used as a mass sensor for bio applications.