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Engineering: Semiconductor Devices

Latest Innovations
Parallel-Kinematics Flexure Stage (PKFS) This parallel-kinematics flexure stage (PKFS) generates a motion range larger than, or at least comparable to, current commercial designs while simultaneously... Read More This parallel-kinematics flexure stage (PKFS) generates a motion range larger than, or at least comparable to, current commercial designs while simultaneously eliminating the undesired secondary motion associated with them. As opposed to traditional positioning systems, parallel kinematics systems, because of their truss-like structures, are structurally stiffer and lighter and allow for high-bandwidth operations. In addition, errors associated with fabrication tend to cancel rather than compound each other. These novel stages are able to produce pure translation, eliminating unwanted translations through the innovative coupling of parallelogram four-bar linkage mechanisms. While further reducing the inertia associated with older designs, this design also increases rigidity and stiffness. Finally, the designs facilitate easy and efficient manufacturing. This invention shows potential uses in many diverse fields, from microscopy and medicine to near-field optical sensing, fields of use where the utmost precision, control, and reliability are critical. This technology is a development in the field of nano-scale positioning stages. The meso-scale, integrated nano-positioning, XY flexure stage can deliver pure translational motion along both the X and Y axes. It accomplishes high motion-resolution while eliminating the troublesome rotational movement often associated with similar devices. Parallel kinematics ensures that the flexure stage does not accumulate errors, but rather it cancels those errors within the kinematic chain. A flexure stage is a positioning stage in which joints are created by introducing weak or flexible areas in an otherwise rigid structure. Under actuating forces, in this case stimulation, flexing at these weak points causes the stage to move, creating the desired change in position. What makes this technology stand out from the rest is the development of a new parallelogram four-bar linkage structure. This novel design generates the desired movement (or flex), without allowing the stage to rotate, and without sacrificing stability. As an example of the capabilities of these stages, the XYZ stage is capable of approximately 50 microns of motion along each axis with sub-nanometer resolution, minimum repeatability of 5nm, and a tracking bandwidth of around 100Hz. Applications: For the user who demands superior control and stability with a fast response in nano-positioning applications. Microscopy Micro-printing Near-field optical sensing Benefits This device provides users with exceptional nano-resolution control of their working stage and offers the pure translational XY and XYZ motion necessary for precision applications. Eliminates undesirable secondary rotational-motion: Stage of positioner will not rotate unpredictably and requires no external corrective devices. Reduces inertia and increases stiffness: Four-bar linkage system increases stability of stage and reduces aberrational, inertial drift. Provides larger work zone: Parallel design offers a larger working stage than that found on other devices with similar resonation frequencies and positioning resolutions. Employs highly linear kinematics: The linear design of this parallel device offers simplicity and stability while increasing user control.
Method for Isolating Antennas Using Meandered-Line Ground Plane Surface Wave Filter A wireless communication device includes multiple antennas spaced apart from each other. Also included is a dielectric substrate with electrically conductive... Read More A wireless communication device includes multiple antennas spaced apart from each other. Also included is a dielectric substrate with electrically conductive ground areas along the substrate opposite the antennas. Signal coupling is decreased between the antennas by connecting the ground areas together with an isolation structure. In one nonlimiting form, this structure includes an electrically conductive meander line structure.
In-Situ Simultaneous Actuation and Displacement Sensing with Electrostatic Actuators Using Amplitude and/or Phase Modulation An electrostatic drive includes a first electrode and a second electrode responsive to a drive signal. The drive signal includes an actuation signal constituent... Read More An electrostatic drive includes a first electrode and a second electrode responsive to a drive signal. The drive signal includes an actuation signal constituent and a sensing signal constituent. The sensing signal constituent is at a frequency higher than a natural mechanical resonant frequency of the electrostatic drive. In response to the actuation signal constituent, displacement between the first electrode and the second electrode changes, which is evaluated by detecting a change in an electrical characteristic of the drive as a function of the sensing signal constituent.
Femto-Joule Atomic Scale Reversible Switch A device that incorporates teachings of the present disclosure may include, for example, a memory array having a first array of nanotubes, a second array of... Read More A device that incorporates teachings of the present disclosure may include, for example, a memory array having a first array of nanotubes, a second array of nanotubes, and a resistive change material located between the first and second array of nanotubes. Other embodiments are disclosed.
High Precision Silicon-on-Insulator (SOI) MEMS Parallel Kinematics Stages MEMS stages comprising a plurality of comb drive actuators provide micro and up to nano-positioning capability. Flexure hinges and folded springs that operably... Read More MEMS stages comprising a plurality of comb drive actuators provide micro and up to nano-positioning capability. Flexure hinges and folded springs that operably connect the actuator to a movable end stage provide independent motion from each of the actuators that minimizes unwanted off-axis displacement, particularly for three-dimensional movement of a cantilever. Also provided are methods for using and making MEMS stages. In an aspect, a process provides a unitary MEMS stage made from a silicon-on-insulator wafer that avoids any post-fabrication assembly steps. Further provided are various devices that incorporate any of the stages disclosed herein, such as devices requiring accurate positioning systems in applications including scanning probe microscopy, E-jet printing, near-field optic sensing, cell probing and material characterization.
Self-Aligning Mechanism for Uniaxial Tests at Micro-Nano Scale and Method for in situ Mechano-Electrical Measurements of Micro-Nano Scale Specimens Current methods of performing tensile tests on micro-nano scale material samples have an inherent flaw, namely that true uniaxial loads are difficult to achieve.... Read More Current methods of performing tensile tests on micro-nano scale material samples have an inherent flaw, namely that true uniaxial loads are difficult to achieve. Part of this stems from the adaptation of macro-scale testing methods to the micro-nano scale, which has been shown to be inadequate. Accordingly, this technology seeks to achieve true uniaxial loads on micro-nano scale material samples to achieve more reliable test results. The current technology is a new method for testing micro-nano scale material samples. It is designed to achieve true uniaxial loads on such materials in a manner different than a mere shrinking of macro-scale tests. The technology achieves this goal all while being able to take mechano-electrical measurements through the use of an SEM or TEM. Finally, the technology can also test material samples in harsh conditions. The technology offers a new method of testing the tensile properties of materials. It offers more accurate and reliable test result compared with technologies which mimic macro-scale testing methods at the micro-nano scale. By employing a new method of testing, the technology can put a more truly uniaxial load on the material sample The material for the testing stage additionally allows these tests to be performed under harsh conditions. For example, the stage and sample may be heated to ~1000_0 C and then tested to see how the material properties change under extreme temperatures. Finally, the technology provides a material independent method. The sample material must be shaped in an appropriate manner for the testing environment; however, any material which can be shaped appropriately may be tested using the instant method. Applications Materials Testing: This technology is for testing the tensile and compression behavior of micro-nano scale materials. MEMS Devices: This serves MEMS based devices well providing more accurate estimates of material behavior allowing for more accurate MEMS devices. Benefits: True Uniaxial Loads: Allows for improved consistency and accuracy of material test results. Material Independent: The testing procedure and self-aligning mechanism are material independent allowing the same apparatus to test a variety of materials In situ Testing in SEM or TEM: Allows mechano-electrical tests to be performed on the material sample at the same time as tensile strength tests.
Optical Control of MEMS Devices Utilizing Photovoltaic Diode An electromagnetic energy, e.g., visible light, controlled low actuation voltage MEMS switch. Stimulation of photovoltaic diodes causes a switching that controls... Read More An electromagnetic energy, e.g., visible light, controlled low actuation voltage MEMS switch. Stimulation of photovoltaic diodes causes a switching that controls the flow of a signal. A metal or other suitable conductive pad moves freely up and down within brackets, without the need for deformation, in response to the diodes to either ground a signal or permit it to pass. The low activation voltage of the bracketed pad structure permits the use of a reasonable number of photovoltaic diodes to develop sufficient voltage for actuation of the switch, allowing the realization of the present electromagnetic energy, e.g., visible light, controlled MEMS switch in a minimized chip area. The photovoltaic diodes do not require an independent DC power source to operate the switch of the invention. Use of different wavelengths to excite different sets of diodes allows turning on and off of the switch of the invention.
A Method for Compensating Wave Reflections in Transmission Lines This technology is a method to eliminate voltage overshoot in cables used to connect AC electric motors and pulse width modulation (PWM) inverters. As a function... Read More This technology is a method to eliminate voltage overshoot in cables used to connect AC electric motors and pulse width modulation (PWM) inverters. As a function of cable length and voltage rise time, voltage overshoot occurs when high frequency currents reflect between the motor and source ends of a cable. University of Illinois researchers have devised a compensator that shapes the output of the PWM inverter in order to eliminate these reflections; the method only requires knowledge of the transmission line characteristic impedance and propagation delay. This technique extends the life of motor insulation and protects voltage-sensitive devices. Voltage overshoot occurs when high frequency currents reflect between the motor and source ends of an electrical cable. Reflective waves of current can build up, causing motor insulation failure as well as damage to voltage-sensitive devices. While there have been techniques developed to compensate for voltage overshoot, many are complex, need load characteristics, and often require the use of bulky and expensive equipment. The University of Illinois technique provides a mathematically exact solution that modifies the output of the PWM inverter in order to eliminate wave reflection. This technique is designed to eliminate voltage overshoot in the cable that connects alternating current (AC) electric motors to pulse width modulation (PWM) inverters that use insulated gate bipolar transistors (IGBT). IGBT motor drive cables are particularly susceptible to voltage overshoot due to their extremely fast switching speeds. The compensator, which attaches to either the source or motor end of a cable, is a filter that uses an appropriate linear combination of voltages and currents to transform the transmission line into a pure delay transfer. This prevents wave reflection and thus voltage overshoot. Users do not need to know the motor or drives characteristics; however, they do need to know the transmission line impedance and the propagation delay in order to use this device. This invention improves on existing solutions to voltage overshoot by providing an exact solution rather than approximation. Applications: The range of applications that use AC motors is vast, examples include: Heavy Industrial Machines or Manufacture: Heavy industries including automotive, materials handling, mining operations, plastic and rubber production, ceramics, textile, and utilities. Workshops: Metalworking, printing and woodworking shops. Chemical Industries: Chemical refining, pharmaceutical production, and plastic fabrication. Benefits Cost-Effective: Eliminates damaging wave reflection, prolonging the usefulness of motors and voltage-sensitive devices. Low-Cost and Small: No large or expensive equipment is needed to implement this technology. Self-Adapting: Modifies waveform as transmission cable properties change over time. Versatile: Can be implemented at either the motor or source side of a cable, allowing users to select the side that is easier to maintain.
Analog to Digital Converter (ADC) with Adaptive Thresholds An adaptive Analog to Digital Converter (ADC) that adjusts the representation levels used in the conversion process so as to optimize system performance. By... Read More An adaptive Analog to Digital Converter (ADC) that adjusts the representation levels used in the conversion process so as to optimize system performance. By establishing system performance criteria by which to select or adjust the signal value range associated with each digital representation and/or the digital representation, substantially fewer bits may be used in the ADC. The systems and methods described herein enable lower-power, smaller form-factor designs as well as very high-speed operation. In particular, this technology may be beneficial for use in communications systems because it enables ADC's to operate at speeds where traditional ADC designs simply cannot.
Low Actuation Voltage Microelectromechanical (MEM) RF Devices A method and apparatus for controlling the flow of signals by selectively switching signals to ground and allowing signals to pass through a signal line based a... Read More A method and apparatus for controlling the flow of signals by selectively switching signals to ground and allowing signals to pass through a signal line based a position of a conductive pad. The switch contains waveguides including the signal line and at least one ground plane. The conductive pad responds to an actuation voltage to electrically connect the signal line and the ground planes when the metal pad is located in a relaxed position. When not located in the relaxed position, the switch breaks the connection to allow signals to flow through the signal line unimpeded. Brackets guide the pad as the pad moves between the relaxed position and a stimulated position due to the actuation voltage, without substantially deforming the conductive pad.

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