An actuator device has a temperature sensing means and a controller adapted to apply a high frequency AC signal to stimulate internal self-heating to thereby maintain a temperature of an actuator member of the device at a certain fixed temperature, this temperature being elevated with respect to an initial temperature of the actuator member. This ensures that thermal drift may be mitigated or eliminated by compensating for any changes in environmental temperature through raising or lowering the level of the heating signal.

A piezoelectric element includes first and second electrodes, a first piezoelectric body layer, and a plurality of first through-hole conductors. The first and second electrodes oppose each other. The first piezoelectric body layer is disposed between the first electrode and the second electrode. The plurality of first through-hole conductors penetrates the first piezoelectric body layer and is connected to the first electrode and the second electrode. When seen in an opposing direction of the first and second electrodes, the plurality of first through-hole conductors is arrayed in a matrix.

A series of multi-dimensional acoustic standing waves is set up inside a growth volume of a bioreactor. The acoustic standing waves are used to hold a cell culture in place as a nutrient fluid stream flows through the cell culture. The nutrient fluid stream dislodges some cells from the cell culture, which can then be recovered for cell therapy applications. The cell culture continues to expand and reproduce, permitting continuous recovery of cells from the bioreactor.

A piezoelectric actuating apparatus including a frame, a rotatable element, an actuating structure, and a sensing structure is provided. The rotatable element is disposed in an accommodating opening and connected to the frame through a rotating shaft structure. The rotatable element is configured to reciprocatingly swing relative to the frame with an axis of the rotating shaft structure. The actuating structure is elastically coupled to the rotatable element through at least one first elastic component. The sensing structure is elastically coupled to the rotatable element through at least one second elastic component. The actuating structure is deformed by receiving a driving signal, and drives the rotatable element to rotate around the axis through the at least one first elastic component. The rotating rotatable element is linked to the sensing structure through the at least one second elastic component to be correspondingly deformed, and outputs a sensing signal.

Technologies for a microelectromechanical system (MEMS) made up of composable piezoelectric actuators is disclosed. An elongated piezoelectric rod is disposed between a top and a bottom electrode. The top electrode runs along one edge of the top of the piezoelectric rod for a first segment, then runs along the other edge of the top of the piezoelectric rod for the a second segment. When a voltage is applied across the electrodes, the piezoelectric rod bends in a first direction for the first segment and in a second direction opposite the first for the second segment, displacing the tip of the rod. Several such rods can be joined in parallel and/or series, allowing for large-scale systems to be composed.

A cantilever fan including a blade and a blade permanent magnet. The blade is clamped at one end to a base and has a distal end which is free to oscillate with distal end having the largest swept displacement of any portion of the blade. The blade extends from the clamped end to the distal end. The blade permanent magnet is attached only to the blade at a point along the blade's length and is free to move with the blade. The fan includes a stationary permanent magnet attached only to the base. The respective locations and relative orientation of the blade permanent magnet and stationary magnet result in a repulsive magnetic force between the blade permanent magnet and stationary magnet. The fan is configured so that the repulsive force increases as the blade's deflection brings the blade permanent magnet closer to the stationary magnet.

A monolithic, bulk piezoelectric actuator includes a bulk piezoelectric substrate having a starting top surface and an opposing starting bottom surface and a at least two electrodes operatively disposed on the bulk piezoelectric substrate consisting of at least two discrete electrodes disposed on either/both of the starting top surface and the starting bottom surface and at least one electrode disposed on the respective other starting bottom surface or starting top surface. A stage includes a base, at least two of the monolithic, bulk piezoelectric actuators disposed on the base, a movable platform disposed on the base, and a respective number of deformable connectors each having a first connection to a respective one of the piezoelectric actuators and a second connection to a respective portion of the movable platform. A method for monolithically making a monolithic, bulk piezoelectric actuator involves a direct write micropatterning technique.

Single bulk unimorph piezoelectric elements, with interdigitated electrodes aligned obliquely relative to the direction perpendicular to the axis of the element, such that a torsional response is induced into the element. When such elements are used as a beam structure, with angularly oriented electrodes on both opposite surfaces of the beam, and with their orientations at mutually opposite angles, motion ranging from pure torsional rotation to pure bending can be obtained, depending on the comparative level and polarity of the voltages applied to each of the two electrode sets. If such elements are used as the spiral support arms of a central platform, a large displacement of the stage can be achieved. Due to the oblique orientation of the IDE's, the piezoelectric transduction induces torsional deformation in the spirals, and this torsion is converted by the spiral arms to a parallel out-of-plane platform motion.

A piezoelectric thin film does not easily generate a heterogeneous phase and exhibits good piezoelectric characteristics. The piezoelectric thin film contains a composition represented by a general formula: (1-n) (K.sub.1-xNa.sub.x).sub.mNbO.sub.3-nCaTiO.sub.3, wherein m, n, and x in the general formula are within the ranges of 0.87?m?0.97, 0?n?0.065, and 0?x?1.

Embodiments of the present disclosure provide a piezoelectric transducer. The piezoelectric transducer may include a piezoelectric layer and an electrode. The electrode may cover at least one surface of the piezoelectric layer, and the electrode or the piezoelectric layer may include a plurality of concave structures recessed in a thickness direction of the electrode or the piezoelectric layer.