Patent ID: 7434918

Claim:
A liquid transporting apparatus comprising: a plate-shaped body including first and second surfaces which are separated from each other by a predetermined distance in a thickness direction and which extend in a predetermined planar direction substantially perpendicular to the thickness direction, and an operation portion having a first portion and a pair of second portions disposed symmetrically on either side of the first portion with respect to the planar direction; at least one electrode located in each of the second portions, the at least one electrode including at least one pair of electrodes to sandwich an active portion, the active portion being defined in each of the second portions between the pair of electrodes and located nearer to the first surface than the second surface in the thickness direction, at least the active portion in the plate-shaped body being formed from piezoelectric material, the at least one pair of electrodes generating an electric field for deforming the active portion in the planar direction, thereby archingly deforming each of the second portions in a direction from one to the other of the first and second portions, and consequently archingly deforming the first portion in an opposite direction from the other to the one of the first and second portions, thereby deforming the operation portion in the thickness direction; a fluid accommodating plate disposed to face one of the first surface and the second surface of the plate-shaped body, the fluid accommodating plate forming a fluid accommodating chamber, the operation portion of the plate-shaped body confronting the fluid accommodating chamber, volume of the fluid accommodation chamber changing in association with the deformation of the first portion and of the pair of second portions to transport fluid in the fluid accommodation chamber; a hole-defining portion defining an ejection hole in fluid communication with the fluid accommodating chamber, change in volume of the fluid accommodation chamber transporting the fluid in the fluid accommodation chamber through the ejection hole; wherein a value of A/(W/2) is not less than 0.33 and not more than 0.75 when W is a length in a radial direction of the fluid accommodating chamber, and A is a length in the radial direction of a portion of the at least one electrode, the portion being formed at an area which overlaps with one side portion in the radial direction of the at least one electrode and an edge portion of the fluid accommodating chamber, the edge portion being other than a central portion of the fluid accommodating chamber.