Transducer and method for forming a transducer

A transducer for converting mechanical stress or vibrations into electric signals, said transducer comprising:

• at least one transducer element;
• at least one dielectric film on at least one side of the transducer element;
• at least one signal electrode;
• at least one ground electrode;
• a transducer part and a connection part;
• wherein the signal electrode layer is arranged in between the dielectric film and transducer element, and
• wherein the transducer element contains at least one permanently charged dielectric cellular electret film.

A transducer for converting mechanical stress and vibrations into electric signals, said transducer comprising:

• at least one transducer element;
• at least one dielectric layer on at least one side of the transducer element;
• at least one signal electrode;
• and
• at least one ground electrode, the transducer having a transducer part and a connection part;
• wherein the transducer element is comprising at least one charged cellular electret film;
• wherein at least the signal electrode is arranged between the dielectric layer and transducer element;
• and
• wherein the signal electrode is essentially inside the transducer structure in order to reduce the electromagnetic interference.

Method for forming a transducer for transforming mechanical stress and vibrations into electric signals, said transducer comprising:

• at least one transducer element;
• at least one dielectric film on at least one side of the transducer element;
• at least one signal electrode, said signal electrode arranged in between the dielectric film and transducer element;
• at least one ground electrode;
• a transducer part;
• a connection part;
• wherein the transducer element is comprised of at least one cellular electret film containing a permanent electric charge;
• forming signal electrodes of several transducers on one or more dielectric films or on cellular electret film material side by side;
• gluing the dielectric films and the cellular electret film material against each other as a laminate so that the cellular electret film is placed in a desired area, said electrodes forming one or more electrically conductive surfaces required at each transducer and
• cutting the laminate into several transducers

A transducer for converting mechanical stress into electric signals, said transducer comprising:

• at least two transducer elements, said elements having first and second surfaces;
• at least one signal electrode layer arranged between two transducer elements, said signal electrode layer being a electrically conductive layer arranged in between the first surfaces of the two transducer film elements;
• and
• at least two ground electrode layers, said ground electrode layers being electrically conductive layers arranged against the second sides of the transducer film elements;
• and said electrodes extend from the transducer part as connection part for connecting the transducer to a signal processing device;
• and
• wherein transducer elements are permanently charged cellular electret films.

Method for forming a transducer comprising following steps:

• arranging at least one signal electrode layer against first surface of a transducer film element;
• arranging at least one signal electrode layer between first surfaces of two transducer elements, the signal electrode layer being a electrically conductive layer;
• and
• arranging ground electrode layers against second surfaces of said transducer film elements;
• wherein transducer part has a unitary laminated structure;
• and
• wherein the transducer elements are permanently charged cellular electret films.

A transducer for converting mechanical stress or vibrations into electric signals, said transducer comprising:

• a transducer part and a connection part;
• a transducer element with a first and a second side;
• a dielectric layer on the first side of the transducer element;
• a ground electrode in between the transducer element and the dielectric layer said ground electrode partially covering said transducer element;
• at least one signal electrode on the second side of the dielectric layer;
• wherein the transducer part has a unitary laminated structure;
• and
• wherein said electrodes continue from the transducer part as a connection part for connecting the transducer to a signal processing device;
• and
• wherein the transducer element is a dielectric cellular electret film containing a permanent electric charge.

Method for forming a transducer for transforming mechanical stress or vibrations into electric signals, said transducer comprising:

• at least one transducer element;
• at least one dielectric film on at least one side of the transducer element;
• at least one ground electrode said ground electrode partially covering said transducer element;
• said ground electrode arranged in between the first side of said dielectric film and transducer element;
• at least one signal electrode, said signal electrode arranged on second side of said dielectric film;
• a transducer part;
• a connection part;
• wherein the transducer element is comprised of at least one cellular electret film containing a permanent electric charge;
• forming said ground electrode of several transducers on one or more dielectric films or on cellular electret film material side by side;
• arranging dielectric films and the cellular electret film material against each other as a laminate so that the cellular electret film is placed in a desired area, said electrodes forming one or more electrically conductive surfaces required at each transducer and
• cutting the laminate into several transducers