California Institute of Technology

The United States of America As Represented by the Administrator of the

Other

The United States of America As Represented by the United States

The United States of America As Represented by the Administrator

Guigne International, Ltd.

Martin B Barmatz

Henry W Jackson

James L Allen

Harry A Atwater

Ruth Amy Brain

Taylor G Wang

William Thomas Pike

Eugene H Trinh

Dan Granett

Nathan Jacobi

John D Mai

Nasser K Budraa

Mark S Gaspar

Gordon Hoover

Daniel D Elleman

Robert P Radtke

Jacques Y Guigne

Steven L Garrett

Sergei V Koptenko

Tzu-yuan Ylin

Glenn Aveni

Mark C Lee

Joseph Rudnick

James D Stoneburner

Seth Putterman

John L Watkins

A method, system, apparatus, and computer readable medium has been provided with the ability to obtain a complex permittivity &#x2208; or a complex permeability &#x3bc; of a sample in a cavity. One or more complex-valued resonance frequencies (f) of the cavity, wherein each fis a measurement, are obtained. Maxwell's equations are solved exactly for &#x2208;, and/or &#x3bc;, using the fas known quantities, thereby obtaining the &#x2208; and/or &#x3bc; of the sample.

Technique for performing dielectric property measurements at microwave frequencies

Bonding of MEMs materials is carried out using microwave. High microwave absorbing films are placed within a microwave cavity, and excited to cause selective heating in the skin of the material. This causes heating in one place more than another. Thereby minimizing the effects of the bonding microwave energy.

Microwave bonding of MEMS component

Bonding of materials such as MEMS materials is carried out using microwaves. High microwave absorbing films are placed within a microwave cavity containing other less microwave absorbing materials, and excited to cause selective heating in the skin depth of the films. This causes heating in one place more than another. This thereby minimizes unwanted heating effects during the microwave bonding process.

Microwave bonding of thin film metal coated substrates

Chemical vapor deposition coating is carried out in a cylindrical cavity. The fibers are heated by a microwave source that is uses a TM N mode, where O is an integer, and produces a field that depends substantially only on radius. The fibers are observed to determine their heating, and their position can be adjusted. Once the fibers are uniformly heated, a CVD reagent is added to process the fibers.

Chemical vapor deposition coating of fibers using microwave application

Chemical vapor deposition coating is carried out in a cylindrical cavity. The fibers are heated by a microwave source that is uses a TM0N0 mode, where O is an integer, and produces a field that depends substantially only on radius. The fibers are observed to determine their heating, and their position can be adjusted. Once the fibers are uniformly heated, a CVD reagent is added to process the fibers.

A method enabling controlled selective heating of workpiece components during microwave brazing. Two workpiece components are joined by melting an adhesion interlayer material between the two components. An indication of when the interlayer has melted is provided. The temperature difference across the braze assembly is monitored and adjusted via a feedback loop to reduce stresses in the braze joint resulting in a stronger braze joint.

Microwave technique for brazing materials

A microwave oven and microwave heating method generates microwaves within a cavity in a predetermined mode such that there is a known region of uniform microwave field. Samples placed in the region will then be heated in a relatively identical manner. Where perturbations induced by the samples are significant, samples are arranged in a symmetrical distribution so that the cumulative perturbation at each sample location is the same.

Uniform batch processing using microwaves

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Method and apparatus for selectively annealing heterostructures using

A microwave plasma assisted method and system for heating and joining materials. The invention uses a microwave induced plasma to controllably preheat workpiece materials that are poorly microwave absorbing. The plasma preheats the workpiece to a temperature that improves the materials' ability to absorb microwave energy. The plasma is extinguished and microwave energy is able to volumetrically heat the workpiece. Localized heating of good microwave absorbing materials is done by shielding certain parts of the workpiece and igniting the plasma in the areas not shielded. Microwave induced plasma is also used to induce self-propagating high temperature synthesis (SHS) process for the joining of materials. Preferably, a microwave induced plasma preheats the material and then microwave energy ignites the center of the material, thereby causing a high temperature spherical wave front from the center outward.

Plasma-assisted microwave processing of materials

A system is described that uses acoustic energy to position an object, which simplifies the application of forces in defined directions to the object and which enables the application of large forces to the object. The system includes transducers (21-24, FIG. 1) that direct separate acoustic beams (31-34) at the object (12), with the system constructed so the beams do not create standing wave patterns. A plurality of beams whose phases at the object are not closely controlled, are directed at different surface areas of the object so the beams do not substantially overlap at the object and create possible canceling effects. A very large force is applied to the bottom (124 FIG. 8) of an object lying in a gravity environment, by directing a plurality of beams (141-145) at the same area at the bottom of the object, and with the beams being controlled so they are substantially in phase at the object area. This plurality of beams can also replace one or all of the transducers (21-24, FIG. 1) to provide much stronger forces to position and manipulate the object. The wavelength (B, FIG. 2) of the acoustic energy in each beam is preferably much less than one-tenth the diameter (C) of the object in order to obtain efficient momentum transfer of energy to the object.

Acoustic beam levitation

A system is described for determining motion of an object that is acoustically positioned in a standing wave field in a chamber. Sonic energy in the chamber is sensed, and variation in the amplitude of the sonic energy is detected, which is caused by linear motion, rotational motion, or drop shape oscillation of the object. Apparatus for detecting object motion can include a microphone (24) coupled to the chamber and a low pass filter (40) connected to the output of the microphone, which passes only frequencies below the frequency of sound produced by a transducer (18) that maintains the acoustic standing wave field. Knowledge about object motion can be useful by itself, can be useful to determine surface tension, viscosity, and other information about the object, and can be useful to determine the pressure and other characteristics of the acoustic field.

Motion measurement of acoustically levitated object

A method for use with an acoustic positioner, which enables a determination of the equilibrium position and orientation which an object assumes in a zero gravity environment, as well as restoring forces and torques on the object, of an object of arbitrary shape in a chamber of arbitrary configuration. An acoustic standing wave field is established in the chamber, and the object is held at several different positions near the expected equilibrium position. While the object is held at each position, the center resonant frequency of the chamber is determined, by noting which frequency results in the greatest pressure of the acoustic field. The object position which results in the lowest center resonant frequency, is the equilibrium position. The orientation of a nonspherical object is similarly determined, by holding the object in a plurality of different orientations at its equilibrium position, and noting the center resonant frequency for each orientation. The orientation which results in the lowest center resonant frequency is the equilibrium orientation. Where the acoustic frequency is constant but the chamber length is variable, the equilibrium position or orientation is that which results in the greatest chamber length at the center resonant frequency.

Acoustic positioning and orientation prediction

Acoustic energy is applied to a pair of locations spaced about a chamber, to control rotation of an object levitated in the chamber. Two acoustic transducers applying energy of a single acoustic mode, one at each location, can (one or both) serve to levitate the object in three dimensions as well as control its rotation. Slow rotation is achieved by initially establishing a large phase difference and/or pressure ratio of the acoustic waves, which is sufficient to turn the object by more than 45.degree., which is immediately followed by reducing the phase difference and/or pressure ratio to maintain slow rotation. A small phase difference and/or pressure ratio enables control of the angular orientation of the object without rotating it. The sphericity of an object can be measured by its response to the acoustic energy.

Acoustic controlled rotation and orientation

A system is described for use with acoustic levitators, which can prevent rotation of a levitated object or control its orientation and/or rotation. The acoustic field is made nonsymmetrical about the axis of the levitator, to produce an orienting torque that resists sample rotation. In one system, a perturbating reflector is located on one side of the axis of the levitator, at a location near the levitated object. In another system, the main reflector surface towards which incoming acoustic waves are directed is nonsymmetrically curved about the axis of the levitator. The levitated object can be reoriented or rotated in a controlled manner by repositioning the reflector producing the nonsymmetry.

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Glendale, CA, United States of America

Martin B Barmatz