Piezoelectric drive device, robot, and drive method thereof

1. A piezoelectric drive device comprising:

a single vibrating plate, an outer periphery of the single vibrating plate being in a longitudinal rectangular shape having top and bottom surfaces, first and second sides opposite to each other, and third and fourth sides opposite to each other, the first and second sides being longer than the third and fourth sides, the single vibrating plate having a plurality of through-holes; and

a plurality of piezoelectric drive units that are disposed on the single vibrating plate, each of the plurality of piezoelectric units having:

a first set of piezoelectric elements that are provided on one of the top and bottom surfaces of the single vibrating plate;

a second set of piezoelectric elements that are provided on the other of the top and bottom surfaces of the single vibrating plate; and

a first projection that is configured to contact a driven body so as to drive the driven body,

wherein the plurality of first projections of the plurality of piezoelectric drive units are all outwardly projected from the first side of the single vibrating plate and are all provided only along the first side of the single vibrating plate,

the plurality of through-holes are located along an outer edge of each of the first set of piezoelectric elements in a plan view, and

wherein the first and second sets of piezoelectric elements are provided at respective same positions corresponding to the top and bottom surfaces of the single vibrating plate.

2. The piezoelectric drive device according to claim 1 ,

wherein each of the first set of piezoelectric elements is configured with a first piezoelectric layer and a pair of first electrodes, and the pair of first electrodes are provided on opposite surfaces of the first piezoelectric layer so that the pair of first electrodes sandwich the first piezoelectric layer.

3. The piezoelectric drive device according to claim 1 ,

wherein tips of the plurality of first projections of the plurality of piezoelectric drive units are on a liner line parallel to the first side of the single vibrating plate.

4. The piezoelectric drive device according to claim 1 ,

wherein each of the second set of piezoelectric elements is configured with a second piezoelectric layer and a pair of second electrodes, and the pair of second electrodes are provided on opposite surfaces of the second piezoelectric layer so that the pair of second electrodes sandwich the second piezoelectric layer.

5. The piezoelectric drive device according to claim 2 ,

wherein each of the first set of piezoelectric elements further has a first substrate, and

one of the pair of first electrodes is formed on the first substrate, the first piezoelectric layer is formed on one of the pair of first electrodes, and the other of the pair of first electrodes is formed on the first piezoelectric layer.

6. The piezoelectric drive device according to claim 5 ,

wherein the single vibrating plate and the first substrate are formed as a monolithic layer.

7. The piezoelectric drive device according to claim 6 ,

wherein the monolithic layer is a silicon substrate.