Abstract: A power generating system comprises a bluff (non-streamlined) body placed in a fluid stream at ninety degrees to the flow direction for creating a von Karman vortex street behind the body. In the process, feedback forces are generated that excite the bluff body into oscillation. The bluff body oscillatory movements are coupled to and energize a power generator. An impedance matching system is employed for electrically varying the natural frequency characteristics of the bluff body such that, over a relatively wide range of fluid flow velocities, the bluff body oscillates at a resonant frequency of the body for maximum energy transfer from the fluid stream to the bluff body.

Abstract: A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

Abstract: A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator for drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows, for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

Abstract: A microelectromechanical (MEM) device for redirecting incident light is disclosed. The MEM device utilizes a pair of electrostatic actuators formed one above the other from different stacked and interconnected layers of polysilicon to move or tilt an overlying light-reflective plate (i.e. a mirror) to provide a reflected component of the incident light which can be shifted in phase or propagation angle. The MEM device, which utilizes leveraged bending to provide a relatively-large vertical displacement up to several microns for the light-reflective plate, has applications for forming an electrically-programmable diffraction grating (i.e. a polychromator) or a micromirror array.

Abstract: A microelectromechanical (MEM) optical switching apparatus is disclosed that is based on an erectable mirror which is formed on a rotatable stage using surface micromachining. An electrostatic actuator is also formed on the substrate to rotate the stage and mirror with a high angular precision. The mirror can be erected manually after fabrication of the device and used to redirect an incident light beam at an arbitrary angel and to maintain this state in the absence of any applied electrical power. A 1×N optical switch can be formed using a single rotatable mirror. In some embodiments of the present invention, a plurality of rotatable mirrors can be configured so that the stages and mirrors rotate in unison when driven by a single micromotor thereby forming a 2×2 optical switch which can be used to switch a pair of incident light beams, or as a building block to form a higher-order optical switch.

Abstract: Microfluidic devices are disclosed which can be manufactured using surface-micromachining. These devices utilize an electroosmotic force or an electromagnetic field to generate a flow of a fluid in a microchannel that is lined, at least in part, with silicon nitride. Additional electrodes can be provided within or about the microchannel for separating particular constituents in the fluid during the flow based on charge state or magnetic moment. The fluid can also be pressurized in the channel. The present invention has many different applications including electrokinetic pumping, chemical and biochemical analysis (e.g. based on electrophoresis or chromatography), conducting chemical reactions on a microscopic scale, and forming hydraulic actuators.

Abstract: The CRC for the CPS Header of an ATM AAL2 cell is generated by a CRC generator which uses the 8 bits of the CID field to generate partial 5 bits CRCs which are loaded in a first table. The 6 bits LI field and 5 bits UUI field are added to the partial 5 bits CRC to form 16 bits. The CRC generator uses the 216 bits to generate a second CRC table. The CRC for a particular CPS header is generated by correlating bits in the CID field, Li field and UUI field with the two tables.

Abstract: A multiple degree of freedom platform assembly formed from a plurality of thin films on a substrate can, when activated, move out of the plane of the substrate without additional manufacturing steps. The platform is connected to the substrate by at least three linkages, each linkage being pivotally connected to the platform and the base. At least two of the base connections are to powered traveling devices that are manufactured at one end of a path and which may be moved to locations along the path to cause the platform to move to predetermined positions. The entire assembly, including hinges, is manufactured as planar structures; preferably by a thin film technology such as MEMS.

Abstract: Microfluidic devices are disclosed which can be manufactured using surface-micromachining. These devices utilize an electroosmotic force or an electromagnetic field to generate a flow of a fluid in a microchannel that is lined, at least in part, with silicon nitride. Additional electrodes can be provided within or about the microchannel for separating particular constituents in the fluid during the flow based on charge state or magnetic moment. The fluid can also be pressurized in the channel. The present invention has many different applications including electrokinetic pumping, chemical and biochemical analysis (e.g. based on electrophoresis or chromatography), conducting chemical reactions on a microscopic scale, and forming hydraulic actuators.

Abstract: A dual-mass microelectromechanical (MEM) resonator structure is disclosed in which a first mass is suspended above a substrate and driven to move along a linear or curved path by a parallel-plate electrostatic actuator. A second mass, which is also suspended and coupled to the first mass by a plurality of springs is driven by motion of the first mass. Various modes of operation of the MEM structure are possible, including resonant and antiresonant modes, and a contacting mode. In each mode of operation, the motion induced in the second mass can be in the range of several microns up to more than 50 &mgr;m while the first mass has a much smaller displacement on the order of one micron or less. The MEM structure has applications for forming microsensors that detect strain, acceleration, rotation or movement.

Abstract: A surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock. Each of two CMG has a first portion of its perimeter devoted to continuous driving teeth that mesh with respective pinion gears. Each EMG also has a second portion of its perimeter devoted to regularly spaced discrimination gear teeth that extend outwardly on at least one of three levels of the CMG. The discrimination gear teeth are designed so as to pass each other without interference only if the correct sequence of partial rotations of the CMG occurs in response to a coded series of rotations from the pinion gears. A 24 bit code is normally input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect.

Abstract: An indexing apparatus is disclosed that can be used to rotate a gear or move a rack in a precise, controllable manner. The indexing apparatus, based on a reciprocating shuttle driven by one or more actuators, can be formed either as a micromachine, or as a millimachine. The reciprocating shuttle of the indexing apparatus can be driven by a thermal, electrostatic or electromagnetic actuator, with one or more wedge-shaped drive teeth of the shuttle being moveable to engage and slide against indexing teeth on the gear or rack, thereby moving the gear or rack. The indexing apparatus can be formed by either surface micromachining processes or LIGA processes, depending on the size of the apparatus that is to be formed.

Abstract: A control system for a vacuum milking system, and a method of controlling vacuum in such milking system. The system comprises an electric vacuum pump motor, a vacuum transducer for providing an output signal that varies as a function of changes in vacuum in the milking line and a variable frequency drive (VFD) connected to the vacuum pump motor and the transducer for controlling the speed of the motor. The VFD varies the frequency of the power signal it provides to the motor as a function of deviation between the output signal from the transducer, which the VFD is programmed to recognize as representative of vacuum, and a setpoint representative of vacuum.

Abstract: Stackable communication network repeater hub capable of performing segmentation while retaining full stack management. Each hub in a stack can control the stack so that if a hub or group of hubs is segmented, one of the hubs is automatically allocated as the master hub. The master hub supplies a synchronizing signal, interprets network commands, and provides control signals for executing the commands.

Abstract: A system and method for controlling a communications adapter interface such that supplemental data can be interleaved with data being transferred. The interleaving is performed in a manner such that the supplemental data is transparent to the data mover portion of the communications adapter. The supplemental data can be transferred in either read or write cycles that are interleaved at the beginning, in the middle, or at the end of data bursts or block data transfers. As a result of the interleaving, the slave interface bus is more fully utilized because arbitration and bus ownership changes do not create unused cycles. The interleaving is accomplished by temporarily halting an existing transfer of data and transferring the requested supplemental data while the data transfer is halted. After the supplemental data is transferred, the transfer of the balance of the data block is then allowed to continue.

Abstract: The material similarity of all-silica waveguides or other devices and optical fibers is utilized to establish an epoxy-free fusion interfacing between optical fibers and integrated-optic devices by using laser welding techniques. This is uniquely applicable to all-silica integrated devices since they have virtually identical material properties to those of optical fibers. The method comprises the steps of machining a locating groove in a silica block, fixing a prepared length of the optical fiber in the locating groove, bringing the block and the device into juxtaposition and aligning the block and the device to provide maximum transmission of a signal from the fiber to the device and laser welding the block and the device together.