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“Dance” has been associated with many psychophysiological and medical health effects. However, varying definitions of what constitute “dance” have led to a rather heterogenous body of evidence about such potential effects, leaving the picture piecemeal at best. It remains unclear what exact parameters may be driving positive effects. We believe that this heterogeneity of evidence is partly due to a lack of a clear definition of dance for such empirical purposes. A differentiation is needed between (a) the effects on the individual when the activity of “dancing” is enjoyedas a dancerwithindifferent dance domains(e.g.,professional/”high-art”type of dance,eroticdance,religiousdance,clubdancing,Dance Movement Therapy(DMT), and what is commonly known ashobby, recreationalorsocialdance), and (b) the effects on the individual within these different domains, as a dancer of thedifferent dance styles(solo dance, partnering dance, group dance; and all the different styles within these). Another separate category of dance engagement is, not as a dancer, but as a spectator of all of the above. “Watching dance” as part of an audience has its own set of psychophysiological and neurocognitive effects on the individual, and depends on the context where dance is witnessed. With the help of dance professionals, we first outline some different dance domains and dance styles, and outline aspects that differentiate them, and that may, therefore, cause differential empirical findings when compared regardless (e.g., amount of interpersonal contact, physical exertion, context, cognitive demand, type of movements, complexity of technique and ratio of choreography/improvisation). Then, we outline commonalities between all dance styles. We identify six basic components that are part of any dance practice, as part of a continuum, and review and discuss available research for each of them concerning the possible health and wellbeing effects of each of these components, and how they may relate to the psychophysiological and health effects that are reported for “dancing”: (1) rhythm and music, (2) sociality, (3) technique and fitness, (4) connection and connectedness (self-intimation), (5) flow and mindfulness, (6) aesthetic emotions and imagination. Future research efforts might take into account the important differences between types of dance activities, as well as the six components, for a more targeted assessment of how “dancing” affects the human body.

This paper reports a CMOS-integrated MEMS microgravity accelerometer that implements a novel four-quadrant symmetric device structure with a full-bridge capacitive output. A robust silicon-on-insulator (SOI) MEMS process integrated with a standard CMOS wafer offers a high-sensitivity, low-noise and low-drift accelerometer that achieves measurement of acceleration in micro-g level. The accelerometers are fabricated and packaged on wafer-level with a silicon cap wafer. The measured sensitivity of the CMOS-integrated accelerometer is at 1.8 V/g with a power dissipation of 6mW at 3 V.

This paper reports the design and analysis of two concepts for shock protection of MEMS using nonlinear springs and soft coatings. The two concepts (nonlinear springs and soft coatings) could improve shock protection by reducing the secondary impact of a moveable MEMS device to shocks stops and by dissipating its energy in a reliable manner. We analyze the merits and demerits of each concept using simulation and ranges of shock design parameters are suggested to enhance performance. Simulations reveal that the nonlinear spring shock stops are capable of reducing impulses by over 90% while soft coatings may reduce impulses by 40%.

This paper reports a high-sensitivity low-noise capacitive accelerometer system with one micro-g//spl radic/Hz resolution. The accelerometer and interface electronics together operate as a second-order electromechanical sigma-delta modulator. A detailed noise analysis of electromechanical sigma-delta capacitive accelerometers with a final goal of achieving sub-/spl mu/g resolution is also presented. The analysis and test results have shown that amplifier thermal and sensor charging reference voltage noises are dominant in open-loop mode of operation. For closed-loop mode of operation, mass-residual motion is the dominant noise source at low sampling frequencies. By increasing the sampling frequency, both open-loop and closed-loop overall noise can be reduced significantly. The interface circuit has more than 120 dB dynamic range and can resolve better than 10 aF. The complete module operates from a single 5-V supply and has a measured sensitivity of 960 mV/g with a noise floor of 1.08 /spl mu/g//spl radic/Hz in open-loop. This system can resolve better than 10 /spl mu/g//spl radic/Hz in closed-loop.

A high-sensitivity capacitive silicon accelerometer with a new device structure is presented in this paper. The structure uses a fixed rigid electrode suspended between a proof mass and a stiff moving electrode to provide differential capacitance measurement and force rebalancing. High sensitivity is achieved by forming a thick silicon proof mass and a narrow uniform air gap over a large area. The mechanical noise floor is reduced by incorporating damping holes in the electrodes. The accelerometer structure is all silicon and is fabricated on a single silicon wafer. The measured sensitivity for a device with 2.6 mm /spl times/ 1 mm proof mass and 1.4 /spl mu/m air gap is /spl ap/11 pF/g per electrode. The calculated mechanical noise floor for the same device is 0.18 /spl mu/g//spl radic/Hz at atmosphere.

This paper presents a complete threshold acceleration detection microsystem comprising an array of threshold accelerometers and a low power interface circuit. The sensors were designed and fabricated using the bulk-silicon dissolved-wafer process. The process offers a wide latitude in sensor threshold levels, as demonstrated in the fabrication of devices with levels of 1.5–1000 g, bandwidths of 45 Hz to 40 kHz, with mass sizes ranging from 0.015 µ gt o 0.7µg, and low-resistance gold–gold contacts for the switch. The interface circuit dissipates less than 300 µW, measures 2. 2m m× 2.2 mm; it was fabricated in-house using a standard 3 µm, p-well CMOS (complementary metal oxide semiconductor) process, and is connected to the sensor chip in a multi-chip module. The key aspects of the microsystem are the implementation of sensor redundancy and supporting circuit logic to improve detection accuracy and fault tolerance, which are crucial factors in many applications. In addition, the microsystem supports communication with a standard microcontroller bus in a smart sensor network.

This paper presents a generic low-power sensor interface chip compatible with smart microsystems and a wide range of capacitive transducers. The interface chip is highly programmable, can communicate with an external microcontroller using a nine-line sensor bus standard, contains a switched-capacitor readout circuit, supports sensor self-test, and includes a temperature sensor. The circuit can interface with up to six external sensors and contains three internal programmable reference capacitors in the range of 0.15–8 pF. The chip measures 3.2×3.2 mm in a standard 3-μm single-metal double-poly p-well process, dissipates less than 2.2 mW from a single 5 V supply, and can resolve input capacitance variations of less than 1 fF in 10 Hz bandwidth.

An open-architecture microsystem that can be populated with a variety of sensors and actuators is described. The microsystem is designed for low-power wireless applications where small size and high sensor accuracy are important. It consists of an in-module microcontroller connected to multiple front-end transducers through an intramodule sensor bus. An external interface allows internally processed data to be output through either a hard-wired input/output port or a radio-frequency transmitter. The present microsystem is configured for environmental monitoring and measured temperature, barometric pressure, relative humidity, and acceleration/vibration. It occupies less than 10 cc, consumes an average of 530 /spl mu/W from 6 V, and transmits data up to 50 m. System features such as active power management, the intramodule sensor bus, generic bus interface circuitry, and in-module sensor compensation based on bivariate polynomials are discussed.

This paper reports an ultra-thin MEMS capacitive pressure sensor with high pressure sensitivity of better than 150aF/Pa, and small die size of 1.0mm × 1.0mm × 60µm. It is able to detect ambient pressure change with a resolution of 0.025% in a pressure range +/−3.5KPa. This capacitive pressure sensor decouples the pressure sensing from its capacitance sensing by using a hermetically sealed capacitor that is electrically isolated but mechanically coupled with a pressure sensing diaphragm such that a large dynamic range and high pressure sensitivity can be readily achieved. Because the capacitor is hermetically sealed in a cavity, this capacitive pressure sensor is also immune to measurement media and EMI (Electromagnetic Interference) effects.

A high-swing, high-drive CMOS buffer amplifier, with good stability over a wide range of capacitive and resistive loads, is presented in this paper. A new area efficient output stage with a relatively small compensation capacitor has been used so that the circuit occupies only 120 mils2 in a 3 μm CMOS technology. The buffer has a drive capability of 110 kHz into a 5000 pF load with a rail-to-rail output swing for load resistances greater than 10 kΩ and acceptable total harmonic distortion with loads down to 270 Ω.

This paper reports the fabrication and testing of integrated nonlinear spring shock stops to protect micromachined devices. This approach enables a generic batch micro-packaging technology providing superior shock protection over conventional hard shock stops, and can be conveniently integrated with micromachined devices without additional fabrication processes and excessive area expansion. These advantages are demonstrated by integrating the nonlinear spring shock stops with a capacitive and with a piezoresistive MEMS accelerometer fabricated by different processes. Conducted shock tests reveal that the nonlinear stops provide substantial device survival rate (83%) compared with hard stops (8%). The device fracture mechanisms are also identified

This paper reports a new technique called “ micro-brush” for easy mechanical attachment and electrical interconnection between two parts. Each of the two parts can be either a single die or a full wafer. They can be attached together in selected areas containing the “ micro-brushe” by simply “ pressing” them together. Each micro-brush is a large array of hair-like high-aspect-ratio metal posts. When pressed together, these metal posts bend and get engaged with others from the opposite side, creating a permanent electrical and mechanical contact, all done at room temperature. High-aspect-ratio arrays of metal posts are fabricated with an areal density of ~ 2,700,000 per cm2. The metal posts can be optionally coated with solder. Test structures have been fabricated and demonstrated mechanical and electrical attachment.

This paper explores the use of transient liquid phase bonding for microsystem packaging applications. Two types of bonds are demonstrated: a thin-film evaporated indium-gold bond and an electroplated nickel-tin bond. Both bonds are formed at 300/spl deg/C for about 1.5 hours in a conventional wafer bonder. The wafers were heated to over 400 /spl deg/C for more than an hour after bonding without any signs of bond degradation. The indium-gold bond demonstrated good electrical contact, but poor permeability performance. However, the nickel-tin bond was void free and sealed cavities with bond ring widths as little as 50 /spl mu/m. The cross section of the nickel-tin TLP bond was analyzed with EDAX software to verify the formation of intermetallic compounds.

This paper reports the design and analysis of two novel concepts for shock protection of MEMS devices using nonlinear springs and soft coatings. Hard shock stops have conventionally been used for shock protection for MEMS devices, but their operation generates secondary impacts and unwanted device oscillations. The two concepts described herein aim to improve shock protection by reducing secondary impacts and dissipating energy. We analyze the merits and demerits of each concept using simulation methods and also suggest ranges of shock stop design parameters to enhance performance. Doing so reveals that the nonlinear spring shock stops are capable of reducing impulses by over 90% while soft coatings may reduce impulses by 40%.

This paper reports a hybrid microinstrumentation system that includes an embedded microcontroller, transducers for monitoring environmental parameters, interface/readout electronics for linking the controller and the transducers, and custom circuitry for system power management. Sensors for measuring temperature, pressure, humidity, and acceleration are included in the initial system, which operates for more than 180 days and dissipates less than 700/spl mu/m from a 6V battery supply. The sensor scan rate is adaptive and can be event triggered. The system communicates internally over a 1MHz, 9-line intramodule sensor bus, and outputs data over a hardwired serial interface or a 315MHz wireless link. The use of folding circuit platforms allows an internal system volume as small as 5cc.

This paper reports the design and analysis of a generic thermal isolation platform that can support a variety of MEMS devices and isolate them from the environment. The platform provides high thermal isolation from the environment by employing long meandering and hollow support metal beams. This isolation is needed for low power (

This paper presents an overview of high precision robust digital control of MEMS nonlinear actuators, in particular torsional electrostatic actuators, using sliding-mode control [N. Yazdi et al. (2003), H. Sane et al. (2004)]. Sliding-mode control enables compact realization of a robust controller tolerant of device characteristic variations, nonlinearities and many types of inherent instabilities. Application of 1/sup st/ order SMC to the control of dual-axis torsional actuators beyond their pull-in limit is demonstrated. Also a modified SMC scheme which uses adaptive switching of the sliding-mode variable differential gain to improve control precision is presented. The modified scheme has resulted in average reduction of 44-56% in output chatter and 70-91% when used for control of several 2-axis gimbaled beam steering micromirrors with a wide range of mechanical characteristics.

This paper presents high-resolution control of torsional electrostatic micromirrors beyond their inherent pull-in instability using robust sliding-mode control (SMC). The objectives of this paper are two-fold - firstly, to demonstrate the applicability of SMC for MEMS devices; secondly - to present a modified SMC algorithm that yields improved control accuracy. SMC enables compact realization of a robust controller tolerant of device characteristic variations and nonlinearities. Robustness of the control loop is demonstrated through extensive simulations and measurements on MEMS with a wide range in their characteristics. Control of two-axis gimbaled micromirrors beyond their pull-in instability with overall 10-bit pointing accuracy is confirmed experimentally. In addition, this paper presents an analysis of the sources of errors in discrete-time implementation of the control algorithm. To minimize these errors, we present an adaptive version of the SMC algorithm that yields substantial performance improvement without considerably increasing implementation complexity.

This paper presents a single chip class D amplifier with 2.5 W output power and 86% efficiency with an 8 ohm load. This chip uses a pulsed width modulation scheme that eliminates the output filter. It operates with a 2.5 V to 6.5 V supply voltage in a 7 V, 1.2 /spl mu/m, double-poly, triple-metal BiCMOS process. It has an area of 1.5 /spl times/ 1.5 mm/sup 2/ and it achieves a THD as low as 0.04%, with a flatband response between 20 Hz and 20kHz.

In this paper we introduce a new electrostatic actuator that provides a large increase in neutral position (no rotation) torque and suppression of pull-in compared to a conventional parallel-plate structure. The actuator geometry incorporates raised electrodes on the side of the rotating element that generate torque versus angle behavior much different than convention parallel plate actuators. Using this electrode configuration we have demonstrated 17-degree stable mechanical rotation on large (950 /spl mu/m diameter) mirrors with 100 V single ended drive-a rotation of 60% of the gap. Driving the mirrors with a differential drive scheme we have demonstrated stable 8-degree rotation with as little as /spl plusmn/18 V.

This paper presents high-resolution control of torsional electrostatic micromirrors beyond their inherent pull-in instability using robust sliding-mode control (SMC). SMC enables compact realization of a robust controller tolerant of device characteristic variations, non-linearities, and many types of inherent instabilities. Robustness of the control loop is demonstrated through extensive simulations and measurements on MEMS with a wide range in their characteristics. Control of two-axis gimbaled micromirrors beyond their pull-in instability with overall 14 milli-degrees pointing accuracy is confirmed experimentally.

In this paper, we demonstrate the application of sliding mode control to a two-axis gimbaled MEMS. The micromirror is a two-axis gimbaled system electrostatically actuated by two pairs of electrodes for each axis. The paper presents a 2-dof coupled dynamic model of a micromirror. The model parameters such as the resonance frequencies, torques and damping are found numerically and verified experimentally. A sliding mode control algorithm with a first-order sliding function is used for implementation. It is shown that the sliding mode control yields a fast and robust switching performance over a range of system parameters in simulation as well as experimentation.

We demonstrate the application of a modified sliding mode control (SMC) scheme with time-constant switching for MEMS micromirror control. This scheme yields substantial performance improvement over previous work, without increasing in implementation complexity. The modification implements a discrete first-order sliding function with a switching time constant and provides the same level of robustness with an added benefit of reduced steady-state error. A two-axis gimbaled MEMS micromirror array designed at Corning-IntelliSense is used for experimental demonstration.

The performance features of MEMS transducers allow the development of a new class of small, low-power sensor microsystems which utilize a suite of sensors to support a wide range of applications. This paper presents a system-level framework for constructing such microsystems where system modularity for application adaptability is a primary design consideration. System architecture, communication protocols, modular packaging, and interface electronics are discussed in general terms, and an implementation of these concepts is presented. Key requirements for microsystem modularity, such as a communication bus and a universal microsensor interface circuit which support plug-n-play operation for online reconfiguration, are developed and presented in this paper.

Four monolithic transformers and an inductor are fabricated in a 5 metal CMOS process with varying number of turns and metal thicknesses. The S-parameters are measured from 500 MHz to 5.5 GHz, and equivalent lumped element models are extracted to calculate the differential quality factor vs. frequency. The transformers demonstrated significantly higher quality factors peaking at higher frequencies compared to the inductor.

High precision accelerometers with /spl mu/g resolution have numerous applications, including inertial navigation and guidance, microgravity measurements, and GPS-aided navigators. In all these applications, in addition to high resolution, the sensor module is required to have good dc response, low offset, and good offset and gain stability. This paper reports a capacitive interface chip for high sensitivity silicon accelerometers. It has 95 dB dynamic range, a low offset of 370 /spl mu/V, and 1/f noise cut-off frequency of

A high-swing, high-drive CMOS buffer amplifier with a good stability over a wide range of capacitive and resistive loads is presented. A new area efficient output stage with a relatively small compensation capacitor has been used. The buffer was designed as a standard cell for analog and mixed mode VLSI applications and the current implementation is in a standard 3- mu m p-well CMOS process. Simulations revealed a drive capability of 140 kHz into a 5000-pF load. The buffer has rail to rail output drive for resistive loads greater than 10 k Omega . The buffer had acceptable total harmonic distribution with loads down to 270 Omega . >

A modified approach for the design of two-dimensional digital filters using singular value decomposition is presented. It is shown that the filters designed by this approach require fewer multiplications. A linear phase response can be achieved for finite impulse response (FIR) designs. >

An architecture for VLSI implementation of multi-layer neural networks is presented in this paper. It is based on direct utilization of external digital weight memory. The architecture lends itself easily to a chip-in-loop training scheme which is controlled by a digital host computer. This architecture has been applied for VLSI implementation of the classifier unit of a moment-invariant contour-shape recognition system. >

Two methods for pipelining analog or hybrid neural networks with analog outputs are presented. These methods provide concurrent operation of various stages on different sets of the network input stream. A new analog neuron with an embedded latch for implementation of one of the architectures is also presented. These methods are particularly attractive for time-multiplexed implementation of multi-layer neural networks. It is shown that significant speed improvement can be achieved by these methods. >

This paper describes a smart microsystem that utilizes a generic interface circuit capable of interfacing with a large variety of capacitive sensors. This wireless microsystem includes a microcontroller for signal processing, sensors that measure temperature, pressure, humidity, and acceleration, and a 315 MHz transmitter for data output. An interface chip handles communication between the microcontroller and the sensors over a standard sensor bus and provides readout circuitry for the capacitive transducers. This interface circuit is highly programmable, can interface with up to six external sensors, supports sensor self-test, and includes three programmable internal reference capacitors in the range of 0.2-12 pF and a temperature sensor. The chip dissipates less than 2.2 mW from a single 5 V supply and can resolve input capacitance variation better than 1 fF.

A complete threshold acceleration detection system is presented in this paper, possessing (i) an array of threshold accelerometers, and (ii) a low power interface circuit. The sensors were designed and fabricated using a modified bulk silicon dissolved wafer process. This process offers a wide latitude in sensor threshold levels, as demonstrated in the fabrication of devices, with levels of 1.5 g to 1000 g, bandwidth of 45 Hz to 40 kHz, with mass sizes ranging from 15 programs to 0.7 /spl mu/grams, and low-resistance gold-gold contacts for the switch. The interface circuit is fabricated in-house, using a standard 3 /spl mu/m, p-well CMOS process and connected to the sensor chip, in a multi-chip module. Additionally, the system employs redundancy, to improve detection accuracy and fault tolerance, which is crucial in many applications. The system also supports communication with a standard microcontroller bus, in a smart sensor environment.

The focus of this study is on a family of hybrid architectures for feed-forward multi-layer neural networks and issues that arise in their design. The main objective in the design of this family has been to reduce the complexity of hardware, and hence make possible the implementation of larger networks for practical applications, by two main ideas: trading time for circuit complexity by a multiplexing scheme and a modular characteristic that allows multi-chip realizations without a prohibitive number of interconnections. In this paper, we propose to bring the various forms of this architecture together, which are at this time scattered in the literature. After presenting the main points in its operation, we will proceed to permutations and trade-offs, some of which have not been published in accessible literature so far. We start with the introduction of the basic architecture. We then present modifications and discuss some I/O issues. Matching neural transfer characteristics is important to the performance of the system and we address this problem with a set of second order improvements. Another version of the architecture, with external weight memory, is introduced which allows interaction with a host computer, and finally, a pipelined version of the architecture is presented that improves system speed with a small increment in overall complexity.

This paper reports a novel all-silicon single-wafer fabrication technology for high precision capacitive accelerometers. This technology combines both surface and bulk micromachining to attain a large proofmass, controllable/small damping, and a small airgap for large capacitance variation. The microfabrication process provides large proofmass by using the whole wafer thickness, and a large sense capacitance by utilizing a thin sacrificial layer. The sense/feedback electrodes are formed by a deposited 2 /spl mu/m polysilicon film with embedded 20-30 /spl mu/m thick vertical stiffeners. These electrodes, while thin, are made very stiff by the thick embedded stiffeners so that force rebalancing of the proofmass becomes possible. The polysilicon electrodes are patterned to create damping holes. Several prototype microaccelerometers are fabricated successfully. Sensitivity of the devices with 2 mm/spl times/1 mm proofmass and full-bridge support are measured to be 2pF/g.

This paper presents a hybrid microaccelerometer subsystem consisting of an all-silicon /spl mu/g capacitive microaccelerometer and a low noise CMOS capacitive interface circuit. This accelerometer has a measured sensitivity of 1.4pF/g for a device with 2mm /spl times/ 1mm proof mass and 1.4/spl mu/m air gap. The calculated mechanical noise floor for the device is 0.39/spl mu/g/vHz in atmosphere. The circuit has a 95dB dynamic range; a low offset of 370/spl mu/V and can resolve better than 75aF. The overall sensitivity of the complete module is measured as 160mV/g with a noise floor of 3.6/spl mu/V/vHz (-110dBV/vHz), indicating that the current system is capable of resolving about 20/spl mu/g/vHz.

Presents a CMOS interface electronics for monolithic micromachined capacitive accelerometer systems. The interface electronics is a fully differential switched-capacitor charge integrator with its internal clock generator and sensor feedback circuit for closed-loop operation. The circuit is designed for open-loop and closed-loop operations, and provides both digital and differential analog outputs. One of the main advantages of this chip is that it can be monolithically integrated with the sensor, resulting in a considerably increased sensor module performance by decreasing the overall system area, minimizing the interface parasitics, and simplifying the packaging. The interface electronics operates at 200kHz sampling clock and provides an adjustable sensitivity between 0.3 and 1.2V/pF with better than 100aF expected resolution resulting in a 93dB dynamic range for 1Hz bandwidth. The total chip dissipates less than 7.2mW power from a single 5V supply, and occupies an area of 3.4/spl times/3.6 mm/sup 2/ in 3/spl mu/m one-metal two-poly p-well. CMOS process of University of Michigan.

Silicon micro-g accelerometers are of increasing demand for the new generation of lightweight low cost inertial measurement units (IMUs) and microgravity measurement systems. This paper presents modeling and noise analysis of a closed-loop micro-g accelerometer with deposited sense and feedback electrodes, and direct digital output. Modeling and noise analysis have been essential to identifying the performance limits in addition to design and development of the accelerometer. The paper first briefly reviews the sensor and its interface electronics, followed by the complete time domain modeling and simulation of the closed-loop electromechanical accelerometer. The simulation results show achievement of less than 10 /spl mu/g direct digital output in a /spl plusmn/1 g range, which is equivalent to 17.6 bits dynamic range. Also, the mechanical and electrical noise analysis indicate a noise floor of 0.72 /spl mu/g//spl radic/Hz without vacuum packaging.

This paper reports an all-silicon fully symmetrical z-axis micro-g accelerometer that is fabricated on a single-silicon wafer using a combined surface and bulk fabrication process. The microaccelerometer has high device sensitivity, low noise, and low/controllable damping that are the key factors for attaining /spl mu/g and sub-/spl mu/g resolution in capacitive accelerometers. The microfabrication process produces a large proof mass by using the whole wafer thickness and a large sense capacitance by utilizing a thin sacrificial layer. The sense/feedback electrodes are formed by a deposited 2-3 /spl mu/m polysilicon film with embedded 25-35 /spl mu/m-thick vertical stiffeners. These electrodes, while thin, are made very stiff by the thick embedded stiffeners so that force rebalancing of the proof mass becomes possible. The polysilicon electrodes are patterned to create damping holes. The microaccelerometers are batch-fabricated, packaged, and tested successfully. A device with a 2-mm/spl times/1-mm proof mass and a full bridge support has a measured sensitivity of 2 pF/g. The measured sensitivity of a 1-mm/spl times/1-mm accelerometer with a cantilever support is 19.4 pF/g. The calculated noise floor of these devices at atmosphere are 0.23 /spl mu/g//spl radic/Hz and 0.16 /spl mu/g//spl radic/Hz, respectively.

A high sensitivity capacitive silicon accelerometer with a new device structure is presented. The structure uses a fixed rigid electrode suspended between a proof mass and a stiff moving electrode to provide differential capacitance measurement and force-rebalancing. High sensitivity is achieved by forming a thick silicon proof mass and a narrow uniform air gap over a large area. The mechanical noise floor is reduced by incorporating damping holes in the electrodes. The measured sensitivity for a device with 2.6 mm/spl times/1 mm proof mass and 1.4 /spl mu/m air gap is /spl ap/100 pF/g. The calculated mechanical noise floor for the same device is 0.18 /spl mu///spl radic/Hz at atmosphere.