The Penn State Research Foundation

US Government As Represented by the Secretary of the Army

Tektronix, Inc.

L Eric Cross

Wenyi Zhu

Nan Li

John Y Fu

Thomas R Shrout

Hue Phuoc Le

Qiming Zhang

Jon C Mutton

Ronald L Adams

J Louis Berger

Baojin Chu

Qing-Ming Wang

Jose Chirvella

Amar Bhalla

Ashvin Srivastava

Qiyue Chia Jiang

An example flexoelectric-piezoelectric apparatus provides an electrical response to an applied force, and/or an actuation in response to an applied electric field, that originates from the flexoelectric properties of a component. For example, shaped forms within the apparatus may be configured to yield a stress gradient on application of the force, and the stress gradient induces the flexoelectric signal. A flexoelectric-piezoelectric apparatus can be substituted for a conventional piezoelectric apparatus, but does not require the use of a piezoelectric material. Instead, the response of the apparatus is due to the generation of stress gradients and/or field gradients.

Flexoelectric&#x2014;piezoelectric composite based on flexoelectric charge separation

An example flexoelectric piezoelectric composite has a piezoelectric response, which may be a direct piezoelectric effect, a converse piezoelectric effect, both effects, or only one effect. The flexoelectric composite comprises a first material, which may be substantially isotropic, the first material being present in a shaped form. The shaped form gives a piezoelectric response due to a flexoelectric effect in the first material. The shaped form may have &#x221e;m symmetry, or a polar variant of this form such as 4 mm symmetry.

Piezoelectric composite based on flexoelectric charge separation

The present invention is a new type of high-strain, pseudo-shear mode piezoelectric ceramic actuator. The pseudo-shear mode actuator employs a stack of pre-poled rectangular ceramic sheets. The stacked sheets form a composite structure assembled from thin sheet soft PZT or PLZT which is poled in the usual direction normal to the major face of the sheet and driven by electrodes upon the major faces. The sheets are conductivity bonded at alternate ends and driven in such a way that alternate sheets expand and contract along the length dimension. Examples of uses would include actuators for linear and rotary motors; step and repeat (inchworm) type actuators; flow sensing and flow control; valving and pumping systems; active noise and vibration control; and large thin panel loudspeakers.

Pseudo-shear mode actuator

A ferroelectric relaxor ceramic actuator material, such as lead magnesium niobate ('PMN'), has high electromechanical conversion efficiency, exhibits wide operating and manufacturing temperature ranges, does not require permanent polarization, and provides useful mechanical activity with reduced electrical drive voltages. A PMN actuator (66) may be bonded to an actuator diaphragm (64) with a high temperature soldering or brazing process. PMN material also has a diffuse Curie point range in which the dielectric constant (40), 'd' coefficient (32), and dielectric loss (42) characteristics all rise to a peak and then fall as the temperature increases. A phase-change ink-jet print head (50) employs a PMN actuator that is compounded with lead titanate ('PT') to increase the temperature (T.sub.M) at which the peak dielectric constant occurs. The print head is operated at a temperature beyond the peak where the PMN:PT actuator 'd' coefficient decreases as the temperature increases such that an increase in ink-jet drop ejection velocity caused by reduced ink viscosity is compensated for by a corresponding reduction in mechanical activity. The PMN:PT actuator thereby relaxes the temperature regulation and heat spreading requirements of the phase-change ink-jet print head.

Ferroelectric relaxor actuator for an ink-jet print head

Process for producing novel fluxed PZT dielectric ceramic compositions having sintering temperatures below about 1000.degree., so as to be non-reactive with electrode layers when co-fired therewith. The PZT is sintered with an effective amount of an eutectic mixture of CuO and an oxide of an alkaline earth metal, preferably barium oxide and/or strontium oxide, to reduce the sintering temperature of the PZT composition below about 1000.degree. C. Dopant such as manganese oxide may be added to reduce the dielectric losses.

PZT ceramic compositions having reduced sintering temperatures and

An electronic ferroelectric length measuring transducer and system for obtaining information and read-in of that information visually to determine the length of an image as well as means to determine if a target is moving. These actions are done very quickly and accurately by changing the polarization of a ferroelectric substrate. In addition, the information, once obtained, can be stored indefinitely without recourse to any external stimuli circuitry, until readout.

Ferroelectric length measuring and moving target transducer with memory

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State College, PA, United States of America

L Eric Cross