A driving circuit for a piezoelectrically actuated pump includes a boost converter, a control circuit and a voltage switch circuit. The boost converter outputs a constant voltage. The control circuit includes a voltage-division circuit, a comparator and a frequency adjustment circuit. The constant voltage is divided by the voltage-division circuit into a first voltage and a second voltage. The comparator compares first voltage with second voltage so as to output a positive voltage or a negative voltage. The voltage switch circuit receives and feedbacks positive voltage or negative voltage to the piezoelectric actuator load. The control circuit and the voltage switch circuit form a resonant circuit to control the piezoelectric actuator load according to the variety of minor voltage outputted form the piezoelectric actuator load. The frequency adjustment circuit detects and adjusts the variety of the minor voltage automatically so as to adjust operating frequency of the piezoelectric actuator load.

A piezoelectric driving device includes: a substrate including a fixed portion, and a vibrating body portion which is provided with a piezoelectric element and is supported by the fixed portion; and a contact portion which comes into contact with a driven body, and transmits movement of the vibrating body portion to the driven body, the contact portion is provided at an end portion in the longitudinal direction of the vibrating body portion, and a difference between a distance between the end portion when the contact portion is not pressed against the driven body and a tip end of the contact portion, and a distance between the end portion when the contact portion is pressed against the driven body and the tip end, is smaller than a total amplitude in the longitudinal direction in a case where the vibrating body portion is driven.

A piezoelectric drive apparatus for a motor, the apparatus including a substrate having a longitudinal direction and a widthwise direction perpendicular to the longitudinal direction, a piezoelectric element provided on the substrate and having a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode, and a contact section that is attached to a front end section of the substrate in the longitudinal direction thereof or in contact with the front end section of the substrate in the longitudinal direction thereof and comes into contact with a driven body, wherein the longitudinal direction of the substrate roughly coincides with a direction in which Young's modulus is minimized in a plane of the substrate.

An electric device includes an electric component that includes an electrode terminal which includes a projection portion, and a circuit substrate that includes a connected portion which is electrically connected to the projection portion, in which the connected portion includes a recess portion that is in contact with the projection portion.

A piezoelectric actuator includes two substrates, piezoelectric elements that are arranged between the two substrates, and a cladding portion that covers at least a part of a surrounding area of the piezoelectric elements.

A piezoelectric driving apparatus including a substrate; a piezoelectric element which has a first electrode provided on the substrate, a piezoelectric body layer provided on the first electrode, and a second electrode provided on the first piezoelectric body layer, a layer including copper provided along an outer periphery of the substrate in plan view and electrically connected to the first electrode; and a conductive layer including nickel and phosphorus provided so as to cover the layer including copper.

A synthetic jet includes a first backer structure, one and only one actuator, a wall member coupled to and positioned between the first backer structure and the one and only one actuator to form a cavity, and wherein the wall member has an orifice formed therethrough, and wherein the orifice fluidically couples the cavity to an environment external to the cavity.