Active multi-layer piezoelectric tactile sensor apparatus and method

A tactile sensing apparatus comprising:

• a. a base material;
• b. a piezoelectric energizing layer disposed on the base material having a plurality of conductors disposed on one surface of a piezoelectric material and a plurality of conductors disposed on the opposite surface on the piezoelectric material, the plurality of conductors having electrical connections adapted to be connected to electrical switching means;
• c. an electrical insulating layer disposed adjacent the energizing layer;
• and
• d. a piezoelectric sensing layer, having conducting surfaces disposed on opposite surfaces thereof, and disposed adjacent the insulating layer, the conducting surfaces adapted to be connected to electrical processing means.

A tactile sensing apparatus comprising:

• a. a first electrode layer having N electrodes, where N.gtoreq.1;
• b. a first piezoelectric layer disposed adjacent to the first electrode layer;
• c. a second electrode layer having M electrodes, where M.gtoreq.1, and disposed adjacent to the first piezoelectric polymer layer wherein N.times.M>1;
• d. an insulating layer disposed adjacent to the second electrode layer;
• e. a first conductive layer disposed adjacent to the insulating layer and adapted to be connected to output processing means;
• f. a second piezoelectric layer disposed adjacent to the first conductive layer;
• and
• g. a second conductive layer disposed adjacent to the second piezoelectric layer and adapted to be connected to output processing means.

A tactile sensing apparatus comprising:

• a. a first piezoelectric energizing layer having a plurality of conductors disposed on one surface of a piezoelectric material and a plurality of conductors disposed on the opposite surface of the piezoelectric material, the plurality of conductors having electrical connections adapted to be connected to electrical energizing means;
• b. a first electrical insulating layer disposed adjacent the first piezoelectric energizing layer;
• c. a second piezoelectric energizing layer having a plurality of conductors disposed on one surface of a piezoelectric material and a plurality of conductors disposed on the opposite surface of the piezoelectric material, the plurality of conductors having electrical connections adapted to be connected to electrical energizing means;
• d. a second electrical insulating layer disposed adjacent the second piezoelectric energizing layer;
• and
• e. a piezoelectric sensing layer having conducting surfaces disposed on opposite surfaces thereof that is disposed adjacent the second insulating layer.

A tactile sensing apparatus comprising:

• a. a first electrode layer having N electrodes, wherein N.gtoreq.1;
• b. a first piezoelectric polymer layer disposed adjacent to the first electrode layer;
• c. a second electrode layer having M electrodes, wherein M.gtoreq.1, and disposed adjacent to the first piezoelectric polymer layer, wherein N.times.M>1;
• d. a first insulating layer disposed adjacent to the second electrode layer;
• e. a third electrode layer having P electrodes, wherein P.gtoreq.1, and disposed adjacent to the insulating layer;
• f. a second piezoelectric polymer layer disposed adjacent to the third electrode layer;
• g. a fourth electrode layer having Q electrodes, wherein Q.gtoreq.1, and disposed adjacent to the second piezoelectric polymer layer, wherein P.times.Q>1;
• h. a second insulating layer disposed adjacent to the fourth electrode layer;
• i. a first conducting layer disposed adjacent to the second insulating layer and adapted to be connected to output signal processing means;
• j. a third piezoelectric polymer layer disposed adjacent to the first conducting layer;
• and
• k. a second conductive layer disposed adjacent to the third piezoelectric polymer and adapted to be connected to output processing means.

A method of operating a tactile sensor comprising:

• a. providing a tactile sensor having a piezoelectric energizing layer with N.times.M energizing areas and N+M connectors for the energizing areas and having a piezoelectric sensing layer adjacent to the energizing layer and electrically insulated therefrom;
• b. providing an alternating frequency electrical signal at a frequency and amplitude adapted to energize the energizing areas;
• c. switching the signal to the N+M connectors in a manner adapted to energize selected energizing areas of the energizing layer in a predetermined sequence;
• and
• d. processing a signal generated by the sensing layer to determine the characteristics of an object that is touching the sensing layer.

A method of operating a tactile sensor comprising:

• a. providing a tactile sensor having a first and second piezoelectric energizing layer with N.times.M energizing areas and N+M connectors on the first layer and P.times.Q energizing areas and P+Q connectors on the second layer, further having a piezoelectric sensing layer disposed adjacent to the second energizing layer and electrically insulated therefrom;
• b. providing an alternating frequency electrical signal at a frequency and amplitude adapted to energize the M.times.N and P.times.Q energizing areas;
• c. switching the signal to the connectors in a manner adapted to energize selected energizing areas of the energizing layer in a predetermined sequence;
• and
• d. processing a signal generated by the sensing layer to determine the characteristics of an object touching the sensing layer.

A method of operating a tactile sensor comprising:

• a. providing a tactile sensor having a piezoelectric energizing layer with N.times.M energizing areas and N+M connectors for the energizing areas and having a piezoelectric sensing layer adjacent to the energizing layer and electrically insulated therefrom;
• b. providing a variable frequency electrical signal at a frequency and amplitude adapted to energize the energizing areas;
• c. switching the signal to the connectors in a manner adapted to energize selected energizing areas of the energizing layer in a predetermined sequence;
• d. generating a signal in the sensing layer that varies in frequency, amplitude, in response to an object in contact with the tactile sensor;
• and
• e. processing the frequency and amplitude information in the signal from the sensing layer to determine the characteristics of the object.

A method of operating a tactile sensor comprising:

• a. providing a tactile sensor having a piezoelectric energizing layer with N.times.M energizing areas and N+M connectors for the energizing areas and having a piezoelectric sensing layer adjacent to the energizing layer and electrically insulated therefrom;
• b. providing a variable frequency electrical signal at a frequency and amplitude adapted to energize the energizing areas;
• c. switching the signal to the connectors in a manner adapted to energize selected energizing areas of the energizing layer in a predetermined sequence and in a manner adapted to eliminate the phantom point problem;
• d. generating a signal in the sensing layer that varies in frequency and amplitude in response to an object in contact with the tactile sensor;
• and
• e. processing the signal from the sensing layer to determine characteristics of the object.

A method of operating a tactile sensor system comprising:

• a. providing a tactile sensor having a piezoelectric energizing layer with N.times.M energizing areas and N+M connectors for the energizing areas and having a piezoelectric sensing layer adjacent to the energizing layer and electrically insulated therefrom;
• b. providing electrical signal energizing and output processing means;
• c. monitoring the electrical output of the sensing layer to determine if an object is in contact with the tactile sensor while keeping the energizing layer and electrical signal energizing means inactive;
• d. switching the tactile sensor system to active status when an output signal is sensed from the sensing layer;
• e. providing an alternating frequency electrical signal at a frequency and amplitude adapted to energize the energizing areas;
• f. switching the signal to the N+M connectors in a manner adapted to energize selected energizing areas of the energizing layer in a predetermined sequence;
• and
• g. processing a signal generated by the sensing layer to determine the characteristics of an object that is touching the tactile sensor.