Strain-sensitive semiconductive thin film electroacoustical transducer

Claim 2

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a resilient electrically nonconductive diaphragm member mounted for bending motion in response to the impingement of low-level pressure waves, said diaphragm having at least one undulating region defined there along, a thin coating of strain-sensitive material having piezoelectric properties deposited on said region, said material having an electrical property which varies as said diaphragm undergoes said bending motion, a biasing conductor on said diaphragm and spaced apart from said strain-sensitive material by a thin insulator such that said transducer has an integrally incorporated source of gain, and means for sensing the variation in said electrical property.

Claim 3

An arRangement as set forth in claim 1 wherein said strain-sensitive material is flanked on both sides by first and second electrically conductive metallic layers respectively and wherein a third metallic layer comprising said biasing conductor overlays said strain-sensitive material, said third layer being disposed in spaced apart electrically insulated relation to said strain-sensitive material and to said first and second layers.

Claim 4

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a flexible diaphragm having first and second annular concentric spaced-apart corregations defined thereon, first and second thin coatings of a strain-sensitive material deposited over said first and second corregations respectively, said material having an electrical property which varies as said corregations are distorted due to the bending of said diaphragm in response to said pressure variation, a first conductive coating deposited between said first and second strain-sensitive coatings and electrically contacting both first and said second strain-sensitive coatings, a second conductive coating deposited adjacent said first strain-sensitive coatings and electrically contacting said first strain-sensitive coatings and a third conductive coating deposited adjacent said second strain-sensitive coating and electrically contacting said second strain-sensitive coating, and means for sensing the variation in said electrical property of said first and second strain-sensitive coatings.

Claim 5

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a flexible diaphragm having first and second annular concentric spaced-apart corregations defined thereon, first and second thin coatings of a strain-sensitive material deposited over said first and second corregations respectively, said material having an electrical property which varies as said corregations are distorted due to the bending of said diaphragm in response to said pressure variation, a first conductive coating deposited between said first and second strain-sensitive coatings and electrically contacting both first and said second strain-sensitive coatings, a second conductive coating deposited adjacent said first strain-sensitive coatings and electrically contacting said first strain-sensitive coatings and a third conductive coating deposited adjacent said second strain-sensitive coating and electrically contacting said second strain-sensitive coating, and means for sensing the variation in said electrical property of said first and second strain-sensitive coatings.

Claim 6

A combination as set forth in claim 3 wherein the electrical impedance of said material varies in relation to the strain applied thereto.

Claim 7

A combination as set forth in claim 3 wherein the relative distortion of said first and second corrugations varies with changes in the frequency of said acoustical pressure variations.

Claim 8

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a resilient electrically nonconductive diaphragm member mounted for bending motion in response to the impingement of low-level pressure waves, having at least one undulating region defined there along, a transistor amplifier integrally formed on said region including a source electrode, a drain electrode separated from said source electrode by a thin coating of strain-sensitive piezoelectric material having an electrical property which varies as said diaphragm undergoes said bending motion and a gate electrode spaced apart from said strain-sensitive material and said source and drain electrodes by a thin insulating material, and means for sensing the variation in said electrical property.

Claim 9

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a resilient electrically nonconductive diaphragm member mounted for bending motion in response to the impingement of low-level pressure waves, having at least one undulating region defined there along, a transistor amplifier integrally formed on said region including a source electrode, a drain electrode separated from said source electrode by a thin coating of strain-sensitive piezoelectric material having an electrical property which varies as said diaphragm undergoes said bending motion and a gate electrode spaced apart from said strain-sensitive material and said source and drain electrodes by a thin insulating material, and means for sensing the variation in said electrical property.

Claim 10

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a flexible ribbon diaphragm member mounted for bending motion in response to the impingement of low-level pressure waves, having a plurality of undulating regions defined there along, a plurality of coatings of a strain-sensitive material deposited over said regions on one side of said diaphragm, said material having an electrical property which varies as said regions are distorted due to the bending of said diaphragm in response to said pressure variations, and means for sensing the variation in said electrical property of said coatings.

Claim 11

A transducer for converting acoustical pressure variations into an electrical signal which comprises, in combination, a flexible ribbon diaphragm member mounted for bending motion in response to the impingement of low-level pressure waves, having a plurality of undulating regions defined there along, a plurality of coatings of a strain-sensitive material deposited over said regions on one side of said diaphragm, said material having an electrical property which varies as said regions are distorted due to the bending of said diaphragm in response to said pressure variations, and means for sensing the variation in said electrical property of said coatings.