Rutgers, the State University of New Jersey

Hoechst Celanese Corporation

USA As Represented by Secretary of the Navy

American Cyanamid Company

Celanese Gmbh

Stratasys, Inc.

American Cyanamid

Ahmad Safari

Stephen C Danforth

Amit Bandyopadhyay

Victor F Janas

Robert E Newnham

Mukesh Agarwala

Rajesh K Panda

Leslie E Cross

Remco Van Weeren

Roger J Card

Michael P O'Toole

Vikram Ramesh Jamalabad

Noshir Langrana

Sei-Joo Jang

Amit Bandyopadghyay

Jayne R Giniewicz

Geon Sagong

William R Priedeman, Jr

John Ballato

Walter A Schulze

Catherine Wilson

Thomas F McNulty

Thomas McNulty

This invention relates to a new class of piezoelectric composites with a radial design. More particularly, the radial design of these new ceramic/polymer composites show a higher sensitivity in the radial direction than conventional tube structured devices. Devices made utilizing this novel design will therefore show significantly enhanced performance in many applications.

Radial ceramic piezoelectric composites

A process for making ceramic composites includes the steps of: a) forming a polymer composition into a three-dimensional mold; b) filling said three-dimensional mold with one or more ceramic containing compositions; c) heating said filled mold to dry and sinter the ceramic; d) removing at least a portion of said three-dimensional mold thereby forming voids; and e) filling the voids with a second composition which has a piezoelectric coefficient which is substantially different from the piezoelectric coefficient of said ceramic structure. Steps a through e yield a controlled, non-random piezoelectric ceramic composite having 2-3, 3-2 or 3--3 connectivity with respect to the sintered ceramic and the second composition throughout the composite.

Methods for producing novel ceramic composites

Solid freeform fabrication techniques are used in direct methods to form photonic bandgap structures, and in indirect methods to form molds for photonic bandgap structures. In the direct methods, solid particulate materials are mixed with a binder and, through a computer-controlled process, are built layer by layer to form the structure. In the indirect methods, unfilled polymeric materials are built layer by layer to form a negative mold for the photonic bandgap structure. The cavities within the mold may then be filled with a slurry incorporating solid particulate materials. Subsequent processing may include mold removal, binder removal, densification and secondary infiltration steps to form a photonic bandgap structure having the desired properties.

Processes for forming photonic bandgap structures

A fused deposition process is used to form three-dimensional solid objects from a mixture including a particulate composition dispersed in a binder. The article is formed by depositing the mixture in repeated layers of predefined thickness, with each layer solidifying before the next adjacent layer is dispensed. Following formation and a binder removal step, the article may be at least partially densified to achieve preselected properties. The process permits three-dimensional articles to be formed relatively quickly and inexpensively, without the need for molds or other tooling.

Solid freeform fabrication methods

A process for forming novel ceramic composites is described. The disclosed process allows for novel composite designs, including composites with regions containing different materials. Moreover, the disclosed process allows for the manufacture of composites with volume fraction gradients of different types of material. Composites with fine-scale microstructures may be formed.

Ceramic composites and methods for producing same

This invention relates to novel oriented piezoelectric ceramic and ceramic/polymer composites. More particularly, it provides a novel piezoelectric composite design wherein the ceramic piezoelectric phase is oriented at an angle with respect to the direction of applied stress, thus giving improved electromechanical properties.

Oriented piezo electric ceramics and ceramic/polymer composites

A disclosed process uses ceramic fiber fabrication technology and allows for novel composite designs, including composites with different polarizable material regions and composites with a gradient in volume fraction of polarizable material. Moreover, composites with fine-scale microstructures may be formed. The new forming method is an improvement to the traditional 'dice and fill' technique currently being utilized to form piezoelectric composites.

Mehtod for making piezoelectric composites

A process for forming piezoelectric composites allows for novel composite designs, including composites with different polarizable material regions and composites with a gradient in volume fraction of polarizable material. Composites with fine-scale microstructures may be formed. The new forming method is an improvement to the traditional 'dice and fill' technique currently being utilized to form piezoelectric composites.

Method for making piezoelectric composites

Superconducting ceramic material is woven into an interconnected structure and embedded in a polymer to produce a flexible, superconducting ceramic material. The polymer also provides protection from moisture. The ceramic polymer composite is fabricated by soaking a carbon fabric in a solution of metal nitrates, ethylene glycol and citric acid to yield a nominal composition of, for example, YBa.sub.2 Cu.sub.3 O.sub.7-x. Heat treatment results in the decomposition of the nitrates, organics and carbon fabric to produce an interconnected structure of the superconducting ceramic material which takes the shape of the original carbon fabric on a reduced scale. In addition, the processing conditions yield significant grain orientation. The superconducting grains of the ceramic material align along the direction of the original fabric weave which provides an improvement of the critical current densities.

Flexible superconducting ceramic polymer composites and method of making

A PET-polymer composite of 0-3 connectivity further includes a third phase particulate additive of conductive or semiconductive material to increase the electrical conductivity of the polymer matrix.

Easily poled 0-3 piezoelectric composites for transducer applications

A hydrophone device is provided with a piezoelectric ceramic-polymer composite of 0-3 connectivity in which the piezoelectric filler comprises a solid solution of PBTiO.sub.3 -BiFeO.sub.3 wherein the solid solution contains 50-80 wt. % of the BiFeO.sub.3. The piezoelectric ceramic-polymer composite has large hydrostatic piezoelectric charge and voltage coefficients which are desirable in hydrophone devices.

Method of detecting sound in water using piezoelectric-polymer

A PZT-polymer composite of 0-3 connectivity further includes a third phase particulate additive of conductive or semiconductive material to increase the electrical conductivity of the polymer matrix.

Piezoelectric ceramic polymer matrices, piezoelectric composites, and methods of make the matrices and composites are disclosed.

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Princeton Junction, NJ, United States of America

Ahmad Safari