The invention relates to a novel ship monitoring
magnetic field sensor based on the ultrasonic sensing and magnetic detection technology. The sensor comprises a
silicon substrate, a
metal electrode, an insulating layer, a piezoelectric film, and a cavity filled with low concentration magnetic fluid. The sensor is characterized in that the sensor can emit or receive an ultrasonic wave, the
viscosity of the magnetic fluid in the cavity is very sensitive to an external
magnetic field, in the condition of no magnetic abnormal source, the sensor carries out
ultrasonic detection in a mode of an
underwater acoustic
transducer, when a magnetic abnormal source appears, the sensor can carry out
ultrasonic detection and magnetic detection at the same time, and the ultrasonic frequency emitted by the sensor can be controlled by applying a bias
magnetic field. The ship monitoring magnetic field sensor is manufactured by using the advanced
micro nano processing technology, the volume is small, the
power consumption is low, the
frequency band is wide, a one-dimensional
line array (1D) and a two-dimensional surface array (2D) can be made, the sensor is compatible with a front-end
electronic circuit, the
mass production of devices is facilitated, and the sensor is suitable for coastal defense, anti
submarine, warship detection, ocean
topography detection and the like.