Bidirectional transducers are transducers in which the electrical quantity can be transformed into a non electrical quantity and vice versa.

Piezoelectric sensors are an example of bidirectional sensors. Force can be converted into an electrical signal. An electrical signal can also be converted into an physical movement or a force.

An inverse transducer is a transducer in which an electrical signal is converted into a non electrical quantity.

An example of an inverse transducer is a piezoelectric transducer in which an electrical signal can be converted into a movement or a vibration.