Abstract: Exemplary practice of the present invention provides a magnetostrictive actuator characterized by linear force output and uniform magnetic biasing. A center bias magnet drives flux through series magnetostrictive bars in opposite directions while surrounding drive coils apply flux in the same direction through the bars. The net response is substantially linear with respect to the drive coil current. A second parallel set of magnetostrictive bars completes the flux path and adds to the actuator output force. Flux leakage between the parallel bars is compensated by a ferromagnetic shunt or by a tapered magnet providing uniform flux density down the length of the magnetostrictive bars. The closed flux path allows magnetic shielding of the entire actuator, if desired.

Abstract: Exemplary practice of the present invention provides a magnetostrictive actuator characterized by linear force output and uniform magnetic biasing. A center bias magnet drives flux through series magnetostrictive bars in opposite directions while surrounding drive coils apply flux in the same direction through the bars. The net response is substantially linear with respect to the drive coil current. A second parallel set of magnetostrictive bars completes the flux path and adds to the actuator output force. Flux leakage between the parallel bars is compensated by a ferromagnetic shunt or by a tapered magnet providing uniform flux density down the length of the magnetostrictive bars. The closed flux path allows magnetic shielding of the entire actuator, if desired.

Abstract: In many uses of electrical motors, the interaction of a tool being powered, e.g., a milling machine, and the workpiece being worked on by the motor induces mechanical vibrations which adversely affect the functioning of the tool as well as inducing wear producing vibrations in the motor rotor shaft. Damping of such vibrations is achieved by deliberately inducing internal unbalanced forces on the motor rotor shaft for counteracting the externally induced vibrations. Such internal unbalanced forces are produced by the use of additional currents in the main stator coils for generating additional, unbalanced force generating magnetic fields. A mathematical analysis of the process is provided.

Abstract: Through-the-lens alignment during deep UV lithographic processing in the manufacture of VLSI is accomplished without shifting the mask or wafer from the exposure position. Introduction and extraction of alignment light of actinic wavelength depends on beam routing due to diffraction from an interference grating. The path of alignment light is within the focusing system but does not impinge on the focused pattern.

Abstract: This disclosure describes a method for producing high-performance layered-element electrostrictive or piezoelectric actuators, and the resulting product. The process calls for steps that minimize decreases of the stack stiffness which usually characterize layered wafer actuators. These include making the wafers flat and parallel, using a referred wafer metalization process that does not affect wafer surface roughness, and using stock-bonding epoxies with viscosities which readily permit the bonding agent to "wick" into the interface areas of the wafer/electrode stacks thereby to minimize the bond agent thickness.

Abstract: Disclosed is an electrodynamic moving coil actuator comprising one or more separate coils contained in interior spaces of a reactance mass. The coils are oriented in closely spaced parallel zones within the interior spaces. The spaces are formed and positioned to be outside of the static magnetic flux lines of the reactance mass. The static flux thus is substantially de-coupled from the dynamic magnetic field of the coil. Magnetic flux choke points are avoided, but at the same time, high volumetric efficiency is achieved. Each coil is attached to supports along its two long outer edges. The supports are connected to each other at their extremities by top and bottom plates which are connected by slide bars that also serve as tie rods. The reactance mass is mounted on the slide bars. The design is adapted to low frequency, high force applications such as active noise control automotive mufflers.

Abstract: A method of making flexible composite piezoelectric materials exhibiting hydrostatic response and having a stable response over time is given. A prepolymer material is combined with a piezoelectric material and polarized by applying an electric field while inducing an electric dipole in the piezoelectric material, typically by applying hydrostatic pressure or changing the temperature. To ensure stable response characteristics, the polymer material is chosen to have a shear modulus of less than 20 pounds per square inch. To help ensure good contact between the piezoelectric material and the polymer material, controlled shrinkage may be induced in the composite materials by heat or the removal of a volatile material. The prepolymer material desirably has an electrical resistivity greater than 10.sup.10 ohm/meters. Typical piezoelectric materials include lithium sulfate and tartaric acid. Typical polymer materials include RTV rubber, urethanes, and polybutadienes, and may be in the form of oligomers.