Abstract:
Techniques are described herein that perform pressure sensing using pressure sensor(s) that include deformable pressure vessel(s). A pressure vessel is an object that has a cross section that defines a void. A deformable pressure vessel is a pressure vessel that has at least one curved portion that is configured to structurally deform (e.g., bend, shear, elongate, etc.) based on a pressure difference between a cavity pressure in a cavity in which at least a portion of the pressure vessel is suspended and a vessel pressure in the pressure vessel.
Abstract:
A system (10) and method detect freefall associated with an object that is spinning or tumbling as it falls. Two tri-axis accelerometers (14, 16) provide inputs to an algorithm (28) that detects the freefall of a spinning object that would not otherwise be detected by a conventional freefall detection system, due to the centrifugal and centripetal forces being placed on the falling object as it spins. The system can be used to detect the freefall of portable devices with onboard memory or hard disk drives, allowing the devices to have time to park the read/write head and reduce the potential of losing data that can be damaged by impact. This freefall detection system may be applied to such portable devices as notebook computers, PDAs, MP3 players, digital cameras, mobile phones and even automobiles.
Abstract:
Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.
Abstract:
A method of manufacturing an insulating micro-structure (100) by etching a plurality of trenches in a silicon substrate (101) and filling said trenches with insulating materials (105, 107). The trenches are etched and then oxidized until completely or almost completely filled with silicon dioxide. Additional insulating material is then deposited as necessary to fill any remaining trenches, thus forming the structure. When the top of the structure is metallized, the insulating structure increases voltage resistance and reduces the capacitive coupling between the metal (109) and the silicon substrate. Part of the silicon substrate underlying the structure is optionally removed further to reduce the capacitive coupling effect. Hybrid silicon-insulator structures can be formed to gain the effect of the benefits of the structure in three-dimensional configurations, and to permit metallization of more than one side of the structure.
Abstract:
A sensor apparatus includes a resonator, a transducer, a damping resistor, a first switch, a filter stage, a second switch, and a noise rejection stage. The transducer is configured to detect a position of the resonator. The damping resistor is configured to electrostatically actuate the transducer and convert a thermomechanical noise of the resonator to an electromechanical noise. The first switch is configured to receive a first signal from the transducer. The filter stage is configured to receive the first signal and adjust a phase and a gain of the first signal and output a filtered first signal. The second switch is configured to receive a second signal from the transducer. The noise rejection stage is configured to receive the filtered first signal and the second signal and reduce the filtered first signal from an output signal.
Abstract:
A calibration unit, system, and method for calibrating a device under test are provided. The calibration unit, system, and method use a single axis rotational unit to calibrate devices under test on a test head. The single axis rotation unit is configured to extend at an angle from a known axis. The test head can be designed in the shape of a frustum with, multiple sides. The calibration unit, system, and method can use combinations of gravitational excitation, Helmholtz coil excitation, and rotational rate excitation for calibrating the device under test. The calibration unit, system, and method can calibrate a 3 degree for freedom or higher MEMS devices.
Abstract:
A calibration unit, system, and method for calibrating a device under test are provided. The calibration unit, system, and method use a single axis rotational unit to calibrate devices under test on a test head. The single axis rotation unit is configured to extend at an angle from a known axis. The test head can be designed in the shape of a frustum with, multiple sides. The calibration unit, system, and method can use combinations of gravitational excitation, Helmholtz coil excitation, and rotational rate excitation for calibrating the device under test. The calibration unit, system, and method can calibrate a 3 degree for freedom or higher MEMS devices.
Abstract:
An accelerometer (100) comprising a silicon wafer is etched to form a fixed portion (400), a movable portion (300), and a resilient coupling (120) between, the fixed and movable portions generally arranged in the plane of the wafer, the mass of the movable portion being concentrated on one side of the resilient coupling. One of the fixed and moveable portions of the silicon structure includes a first electrode. The other of the fixed and moveable portions includes a second electrode oriented parallel to the axis of acceleration, and an electrically-conductive layer electrically connected as a third electrode coplanar and mechanically coupled with the second electrode. The second and third electrodes are arranged in capacitive opposition to the first electrode, the capacitance between the first electrode and third electrode increasing as the movable portion moves in a direction along the axis of acceleration relative to the fixed portion and decreasing as the movable portion moves in an opposite direction. A resilient coupling retains the first and third electrodes in capacitive opposition to each other across a capacitance gap while allowing motion of the first electrode relative to the second and third electrodes in response to acceleration along an axis of acceleration perpendicular to the plane of the wafer, and resiliently restores the first electrode to an equilibrium position when the acceleration ceases. The second electrode is in opposition to a majority of the surface area of the first electrode when the electrodes are in the equilibrium position. Capacitance between the first and third electrodes is measured to obtain a measurement of acceleration along the axis.
Abstract:
A method for etching an ultra-shallow channel includes using an etch process that is selective for one material to etch a different material in order to achieve a very precise channel depth in the different material. Channels as shallow as 10nm can be fabricated in silicon with precisions of 5nm or better using the method. Stepped channels can be fabricated where each segment is a different depth, with the segments being between 10nm and 1000nm in depth. The method is applied to creat a fluidic channel which includes a channel substrate to which is bonded a lid substrate to confine fluids to the fluidic channels so fabricated.
Abstract:
Accelerometers are described herein that have RMS outputs. For instance, an example accelerometer may include a MEMS device and an ASIC. The MEMS device includes a structure having an attribute that changes in response to acceleration of an object. The ASIC determines acceleration of the object based at least in part on changes in the attribute. The ASIC includes analog circuitry, an ADC, and firmware. The analog circuitry measures the changes in the attribute and generates analog signals that represent the changes. The ADC converts the analog signals to digital signals. The firmware includes RMS firmware. The RMS firmware performs an RMS calculation on a representation of the digital signals to provide an RMS value that represents an amount of the acceleration of the object.