Patent ID: 8016392

Claim:
A liquid transport apparatus which transports a liquid, comprising: a channel unit which has a liquid transport channel through which the liquid is transported and a pressure chamber formed in the liquid transport channel; a piezoelectric actuator which applies a pressure to the liquid in the pressure chamber and which has a first piezoelectric layer, a second piezoelectric layer, a first electrode, a second electrode, and a third electrode, the first piezoelectric layer covering the pressure chamber and polarized in a thickness direction of the first piezoelectric layer, the second piezoelectric layer being joined to a surface, of the first piezoelectric layer, on a side not facing the pressure chamber and polarized in a thickness direction of the second piezoelectric layer, the first electrode being formed on a surface of the first piezoelectric layer, on a side facing the pressure chamber, at a portion facing the pressure chamber, the second electrode being formed on a surface of the second piezoelectric layer, on a side not facing the first piezoelectric layer, at a portion facing the pressure chamber, the third electrode being formed between the first piezoelectric layer and the second piezoelectric layer at a position at which the third electrode faces the pressure chamber; a driving mechanism which drives the piezoelectric actuator and which has a potential applying mechanism applying potentials to the first electrode, the second electrode, and the third electrode respectively, and a controller controlling the potential applying mechanism; wherein the controller controls the potential applying mechanism to switch between a first state and a second state, the first state being a state in which the first electrode and the third electrode have a potential difference and the second electrode and the third electrode are at a same potential, and the second state being a state in which the second electrode and the third electrode have a potential difference and the first electrode and the third electrode are at a same potential.