Sensor devices with liquid-filled cavity and air cavity

A sensor device, comprising:

• a housing, the housing having an accommodating cavity;
• a transducer unit, including a vibration pickup structure configured to pick up a vibration of the housing and produce an electrical signal, the transducer unit in the accommodating cavity separating the accommodating cavity to form a front cavity and a rear cavity located on opposite sides of the vibration pickup structure, wherein at least one cavity of the front cavity and the rear cavity is filled with liquid, the liquid is in contact with the vibration pickup structure, and an air cavity is formed between the liquid and the housing, wherein the housing further has a gas cavity, one cavity of the front cavity and the rear cavity is filled with the liquid, and the gas cavity is communicated with another cavity of the front cavity and the rear cavity that is not filled with the liquid.

A sensor device, comprising:

• a housing, the housing having an accommodating cavity;
• a transducer unit, including a vibration pickup structure configured to pick up a vibration of the housing and produce an electrical signal, the transducer unit in the accommodating cavity separating the accommodating cavity to form a front cavity and a rear cavity located on opposite sides of the vibration pickup structure, wherein at least one cavity of the front cavity and the rear cavity is filled with liquid, the liquid is in contact with the vibration pickup structure, and an air cavity is formed between the liquid and the housing, wherein the transducer unit includes a substrate structure, a layered structure, and at least one damping structure layer, a damping of the at least one damping structure layer being different under different stress states.