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A nano-gravimetric detector (NGD) for gas chromatography is based on a nanoelectromechanical array of adsorbent-coated resonating double clamped beams. NGD is a concentration-sensitive detector and its sensitivity is analyte-dependent based on the affinity of the analyte with the porous layer coated on the NEMS surface. This affinity is also strongly related to the NGD temperature (NGD working temperature can be dynamically set up from 40 to 220 °C), so the sensitivity can be tuned through temperature detector control. An adsorption-desorption model was set up to characterize the NGD response on a large set of n-alkanes from C10 to C22 at different NGD temperatures. For fast identification of petroleum mixture based on chromatogram fingerprint, a general strategy for NGD temperature program design was developed leading to a constant relative response factor between 0.96 and 1.03 for all the alkanes, and then chromatograms are very similar to those obtained with a flame ionization detector (FID). The analysis of a real petroleum fluid was also performed and compared to FID results: quantitative results obtained for all the analytes were satisfactory according to precision (

This brief presents an active distributed clock generator for manycore systems-on-chip consisting of a $10\times 10$ network of coupled all-digital phase-locked loops, achieving less than 38 ps phase error between neighboring oscillators over a frequency range of 700–840 MHz at $V_{\text {DD}} = 1.1$ V. The network is highly robust against $V_{\text {DD}}$ variations. An energy cost of 2.7 $\mu \text{W}$ /MHz per node is 7 times lower than that in analog implementations of similar architectures and is twice lower than that in conventional H-tree architectures. This is the largest on-chip all-digital phase-locked loop network ever implemented. With clock generation nodes linked only locally, this solution is proven to be scalable. The presented clock generation network does not require any external reference, except for the start-up frequency selection, generating a synchronized signal in fully autonomous mode and maintaining frequency stability within 0.09% during 1700 seconds. Such a network of frequency and phase synchronized oscillators can be used as a source for local clocking areas.

One of the main challenges to overcome to perform nanomechanical mass spectrometry analysis in a practical time frame stems from the size mismatch between the analyte beam and the small nanomechanical detector area. We report here the demonstration of mass spectrometry with arrays of 20 multiplexed nanomechanical resonators; each resonator is designed with a distinct resonance frequency which becomes its individual address. Mass spectra of metallic aggregates in the MDa range are acquired with more than one order of magnitude improvement in analysis time compared to individual resonators. A 20 NEMS array is probed in 150 ms with the same mass limit of detection as a single resonator. Spectra acquired with a conventional time-of-flight mass spectrometer in the same system show excellent agreement. We also demonstrate how mass spectrometry imaging at the single-particle level becomes possible by mapping a 4-cm-particle beam in the MDa range and above., Nano-electro-mechanical system-based mass spectrometry holds promise for detecting supramolecular assemblies at large molecular weights, but its efficiency is too poor to be practical. Sage et al. overcome this problem using a nanomechanical resonator array, which significantly decreases detection time.

The miniaturization and cost reduction of a gas chromatograph is addressed in this paper, leveraging on nanoelectromechanical systems (NEMS) detectors and a mixed-signal integrated circuit. The instrument and chip architectures are thoroughly described, characterized, and compared to other approaches like thermal conductivity detectors (TCDs). The 28 nm CMOS circuit addresses the sequential and parallel driving and readout of NEMS arrays with resonance modes in the 10 MHz to 1 GHz range. It integrates an analog-to-digital converter (ADC), two digital-to-analog converters (DACs), and 4 tone DSP [lock-in amplifier (LIA) and direct digital synthesizer (DDS)] for increased throughput. Its area is ${{0}}.{{9}}\;{\text{m}}{{\text{m}}^2}$ and it draws 68 mW of power compared to ${{10}}\;{\text{c}}{{\text{m}}^2}$ and 3 W in previous discrete implementations. Lab and field characterizations show that the combined NEMS and IC can provide down to 10 ppb limits of detection (LOD) on selected gas species.

International audience; The evolutions of medicine covering genome to exposome (i.e. all types of environmental exposures) [1] opened new paths of development for electronics including low power sensors. Additionally, the frontiers for new generations of sensors between smart-living, environment and health are fading. In this paper, we will give examples based on our developments in emerging autonomous sensors and medical devices, and show how they can be included in our daily life

In this paper, the problem of the control law design for interconnected identical systems ensuring the global stability and the global performance properties is under consideration. Inspired by the decentralized control law design methodology using the dissipativity input-output approach, the problem is reduced to the problem of satisfying two conditions: (i) the condition on the interconnection and (ii) the condition on the local subsystem dynamics. Both problems are efficiently solved applying a (quasi-) convex LMI optimization and standard H∞ synthesis. The proposed design methodology is applied to the control law design of a synchronous PLL network.

In this work, a comprehensive, predictive and quantitative model of a whole gas analyzer is provided in order to facilitate the design of such high performance devices. All the pre-analytical (gas separation) and analytical (detection and readout) stages have been modeled and experimentally calibrated. Heterogeneous simulations have been used to quantify the impact of the whole architecture on the output characteristic of the gas analyzer. Finally, the model of the NEMS sensor and the chromatography micro-column assembly has been experimentally validated with TEOX (toluene, ethylbenzene, octane, and xylene) gases.

We report a novel NEMS-based heterodyne self-oscillator. By using a downmixing detection scheme, the NEMS motion piezoresistive signal at 20 MHz is shifted down to few tens of kHz, thus avoiding the negative impact of stray capacitances. This technique allows the NEMS self-oscillator to benefit from its major advantages: a high dynamic range and a high signal to background ratio. However in this form, the signal cannot be directly inserted in a standard oscillator feedback loop since the output signal is neither proportional, nor at the same frequency as the NEMS actuation signal. This paper describes a novel heterodyne architecture so that self-oscillation motion of the NEMS builds up with excellent frequency stability. By providing a high dynamic range and high signal to background ratio, this feedback loop architecture represents an efficient way to track NEMS resonance frequency in real time, as required in sensing applications like mass sensors.

This work presents a technique to cancel the parasitic feedthrough current in a fully CMOS integrated electrostatic micromechanical resonator. A four-electrode balanced topology has been proven to enhance the measured response of a polysilicon clamped-clamped beam resonator. The test results obtained show a pure RLC behavior of the resonator at 10.98MHz.

These last 10 years, smaller, less expensive, and higher performance sensors are required for gas sensing applications. To date no true detection principle has been recognized as the best candidate for such application. Microsytems or Micro/Nano Electro Mechanical Systems (M/NEMS) used as gravimetric detectors are among the probable candidates. The technology can indeed be manufactured en masse and can provide multi-gas analysing platform. In this paper, we present a comprehensive overview of micro/nano sensors based on the gravimetric effect to detect an absorbed gas on top of their surfaces. The paper provides a comparison between different electromechanical devices (Bulk Acoustic Wave, Surface Acoustic Wave, Capacitive Micro-machined Ultrasonic Transducer, Micro/Nano cantilevers) with an introduction to gas adsorption mechanisms, material selection, detection principles and design guidance useful to researchers or engineers.

The paper reports on an integrated device combining a single-crystal silicon NEMS with an embedded MOS transistor in transconductance configuration fabricated with a simple and low cost technology based on localized Silicon on Nothing technology. Thanks to the high transconductance achievable, this approach enables NEMS with embedded MOS transistors for enhanced readout efficiency.

This abstract presents the design, the fabrication and the measurements of a very small and sensitive resonantaccelerometer. The sensor is based on a strain sensitive vibrating beam attached to a mass. The vibration of thebeam is electrostatically driven and the detection of the signal is capacitive. The sensor is fabricated thanks to potential ”In-IC” compatible thin SOI-based technologies, allowing the patterningof submicron gaps. The beam dimensions are at the micron scale while the gap used in the capacitive detection is inthe nanometer range (750 nm). The sensitivity of the accelerometer is measured with a phase lock loop (PLL) built using a lock-in amplifier (LIA)controlled with a computer program. The measured sensitivity is 22 Hz/g and the maximum resolution is smallerthan 5 mg (5Hz integration bandwidth). The results presented in this paper show that the miniaturization of resonant accelerometers can lead to a goodsensitivity and resolution.

In this paper, we present a new weighted least-squares (WLS) approach for parameter estimation based on binary data. Two WLS criteria are studied. We show that these two criteria do not have the same asymptotical behavior although they are closely related. Particularly, in the presence of noise, one of the criteria used for determining the system parameters provides an appropriate estimation, whereas the other one leads to an underestimation of the system parameters. These asymptotical results are illustrated by simulations in Gaussian and non-Gaussian contexts.

NEMS based sensors open several opportunities for integrated solutions in emerging domains as chemical analysis and life science. With critical dimensions ranging between 10 and 100 nm, those devices can be made at the VLSI scale, possibly co-integrated with CMOS and are well suited for autonomous, highly sensitive or dense sensors. Several applications will be presented, as complex gas portable recognitions systems, mass spectrometry, or bio-sensors.

This paper presents NEMS gas sensors implemented in a breakthrough multigas analysis system. The NEMS mass sensors are collectively fabricated, functionalized and packaged at wafer level. NEMS array resonators exhibit good frequency stability (Allan deviation

Progress in silicon technology has promoted NEMS sensors as viable and highly sensitive candidates for gravimetric applications such as gas sensing, mass spectrometry and biochemical analysis [1]. The high sensitivity to mass is related to the small dimensions and intrinsic mass of the NEMS themselves, which results in resonant frequencies in the 10MHz-to-1GHz range and drive voltages reaching 1V to 10V. Such a combination of frequencies and voltages is a challenge for the driving electronics. Although several promising approaches using NEMS/CMOS co-integration have been recently published [2], many experiments in the field are currently using discrete electronic boards and specialized lab instruments. To respond to size, power and cost demands, an IC implementing the most critical parts of the full system is described hereafter.

This paper reviews the last major realizations in the field of monolithic integration of NEMS with CMOS. This integration scheme not only drastically improves the efficiency of the electrical detection of the NEMS motion. Our analysis is that it also represents a compulsory milestone to practically implement breakthrough applications of NEMS, such as mass spectrometry, that require large capture cross section (VLSI-arrayed NEMS) and individual addressing (co-integration of NEMS arrays with CMOS for closed-loop operation).

This work reports on top-down nanoelectromechanical resonators, which are among the smallest resonators listed in the literature. To overcome the fact that their electromechanical transduction is intrinsically very challenging due to their very high frequency (100 MHz) and ultimate size (each resonator is a 1.2 μm long, 100 nm wide, 20 nm thick silicon beam with 100 nm long and 30 nm wide piezoresistive lateral nanowire gauges), they have been monolithically integrated with an advanced fully depleted SOI CMOS technology. By advantageously combining the unique benefits of nanomechanics and nanoelectronics, this hybrid NEMS-CMOS device paves the way for novel breakthrough applications, such as NEMS-based mass spectrometry or hybrid NEMS/CMOS logic, which cannot be fully implemented without this association.

We describe a method for exciting a micro-mechanical resonator using short pulsed forces. A brief impulse excites the system whenever it passes its position of equilibrium, thus bringing it to oscillate. This actuation strategy is described from a theoretical point of view and a possible application to the case of a resonant accelerometer is presented. Results of the simulation of the entire process, obtained with VHDL–AMS, are given and commented. This actuation scheme offers several advantages: it can be applied to several sorts of excitation techniques; it reduces possible non-linearity problems; such as those associated with electrostatic actuation; it does not require any special design of the oscillating microstructure (as opposed to linear comb-drives solutions). Additionally, the electronic circuitry needed to realize the system is simple and is therefore a good alternative to other techniques for driving MEMS at resonance.

978-1-4799-3431-7; International audience; In this review paper, we define and discuss the concept of complexity for heterogeneous systems. Due to the current progress in fabrication technology, modern micro-scale integrated systems may have a large number of interacting elements. Each of those elements not only displays its own dynamical properties, but also, in the most general case, can be nonlinear or can belong to different physical domains. We consider two different examples of systems that are complex in the terms we use in this paper. The first example is a network of oscillators and is heterogeneous since it is a mixed-signal system. The second example is an electrostatic vibration energy harvester, a micro scale system combining elements from the mechanical and electrical domains. In both cases we discuss the challenges that arise at the stage of the system design.

We report on the first experimental demonstration of a self-oscillator based on a single-crystal silicon NEMS resonator monolithically co-integrated with a CMOS circuitry. The latter, composed only by seven transistors, is manufactured with a very low-cost 0.35μm technology. The NEMS-CMOS self-oscillator pixel is as small as 50×70 μm2 (pads excluded) and can oscillate near 8MHz. In this paper are described the NEMS-CMOS oscillator characteristics and the implementation method of the self-oscillating loop.

Based on experimental results and a dedicated model, the impact of various technological parameters on the performance of a frequency addressed NEMS arrays sensor is investigated for mass sensing application. It is shown that the number of NEMS resonators that can be addressed in parallel is limited by critical dimensions fluctuations, the quality factor of the NEMS and their resonance frequencies.

This paper reports the design, fabrication and characterization of NEMS resonator arrays along with their associated readout scheme enabling the probing of all the resonators within an array. The successful monitoring of arrays of 20 NEMS in both air and vacuum is presented and the significant advantage these arrays provide over individual resonators for mass and gas sensing is discussed. Arrays of 20, 49 and 100 resonators have been designed and characterized in terms of Signal to Background Ratio (SBR) of the NEMS frequency response and Allan Deviation (ADEV) for the frequency stability of the resonators. While probing an array in closed loop, mass additions onto the NEMS were simulated by electrostatically-induced frequency shifts. These shifts were applied simultaneously on the entire array to demonstrate the ability of this system to track the complete array in real time. On the other hand, a noise reduction at short integration times by a factor close to √N, where N is the number of resonators, has been obtained by averaging all the resonators' signal. The ability to control arrays of NEMS with a simplified routing and a reduced number of electrical connections is demonstrated and the great potential of NEMS arrays for gas and mass sensing applications is highlighted.

This work constitutes the first demonstration of monolithic integration of single-crystal silicon capacitive NEMS resonators with CMOS. With this approach, the efficiency of the electrical detection of the NEMS motion is outstanding and achieved with only seven transistors that are fabricated with a completely unmodified and very low-cost 0.35μm bulk CMOS technology.

In this paper, we will present some possible emerging applications for Nano-Electro-Mechanical Systems (NEMS) and the interest of their co-integration with CMOS. We will compare some integration schemes and present mass sensing as a possible emerging application. In particular, experimental results on complex gas measurements with NEMS will be introduced. We will show that multi-physics simulations and compact modelling of NEMS components (including chemical and physical effects) can be efficiently used in circuit simulations standard tools for such system optimization.

We have developed arrays of nanomechanical systems (NEMS) by large-scale integration, comprising thousands of individual nanoresonators with densities of up to 6 million NEMS per square centimeter. The individual NEMS devices are electrically coupled using a combined series-parallel configuration that is extremely robust with respect to lithographical defects and mechanical or electrostatic-discharge damage. Given the large number of connected nanoresonators, the arrays are able to handle extremely high input powers (>1 W per array, corresponding to

Similar to transistors, the size of MEMS components is continuously shrinking, progressing from MicroElectroMechanical Systems to NanoElectroMechanical Systems (NEMS). Indeed, NEMS are emerging as a new field of interest because their submicron dimensions make them converge towards CMOS fabrication processes. They have specific advantages such as fast response time and high detection sensitivity when used as a resonant sensor [1]. From the application point of view, NEMS interact “naturally” with the nanoscale world and can sense unprecedented physical and biological phenomena, such as the mass of a single molecule, the force exerted by living cells or certain biochemical reactions. In the next five to ten years, NEMS should offer a real breakthrough for mass spectrometry or gas analysis applications because they can achieve similar resolution to conventional lab equipment but at a lower cost due to their compatibly with VLSI processes.

This paper reports on ultra-scaled single-crystal Si NEMS resonators (25–40nm thick) operating in the 10–100MHz frequency range. Their first monolithic integration at the front-end level with CMOS enables to extract the signal from background leading to possible implementation of direct/homodyne measurement, for high sensitivity sensing applications and portable systems.

ISBN: 978-1-4577-0506-9; International audience; This work demonstrates for the first time a VLSI-compatible nano/microfabricated, high-performance, portable multi-gas analyzer associating gas chromatography and NEMS resonators.

International audience; This work proposes a generic methodology to evaluate the feasibility of designing a Pierce oscillator based on a micro or nanoresonator fabricated with any given CMOS technology and with the constraint of using only one single active transistor. Both the design and the transimpedance gain of the electronics are analytically determined for resonators with capacitive or resistive detection. This approach is applied and validated in the case of (a) an electrostatically actuated clamped-clamped beam resonator using a capacitive transduction, and (b) a piezoresistive crossbeam, both based on a standard 0.13 μm CMOS technology.

International audience; In this paper, the problem of active clock distribution network synchronization is considered. The network is made of identical oscillators interconnected through a distributed array of phase-locked-loops (PLLs). The problem of the PLL network design is reformulated, from a control theory point of view, as a control law design for a distributed multi-agent system. Inspired by the decentralized control law design methodology using the dissipativity input-output approach, the particular topology of interconnected subsystems is exploited to solve the problem by applying a convex optimization approach involving simple Linear Matrix Inequality (LMI) constraints. After choosing the dissipativity properties which is satisfied by the interconnection matrix, the constraints are transformed into an H ∞ norm constraint on a particular transfer function that must be fulfilled for global stability. Additional constraints on inputs and outputs are introduced in order to ensure the desired performance specifications during the H ∞ control design procedure.

In this paper, we demonstrate the high sensing performances of a DMMP vapor sensor system based on 50 nm thick AlN film microcantilevers. These devices are particularly interesting for low power integrated gas sensors systems. One key factor for their gas sensing performances optimization relies on the reduction of the AlN layer thickness. Thanks to a digital PLL setup we demonstrate high frequency stability with an Allan deviation of 5.10−8. Finally, using DKAP polymer for surface functionalization of the cantilever, we measure DMMP vapor concentration down to 25 ppb and predict from frequency noise an ultimate resolution of 10 ppb at the level of the state of the art of DMMP sensing.

International audience; This brief addresses the problem of clock generation and distribution in globally synchronous locally synchronous chips. A novel architecture of clock generation based on network of coupled all-digital PLLs is proposed. Solutions are proposed to overcome the issues of stability and undesirable synchronized modes (modelocks) of high-order bidirectional PLL networks. The VLSI implementation of the network is discussed in CMOS65 nm technology and the simulation results prove the reliability of the global synchronization by the proposed method.

International audience; This paper presents a CMOS 1.1-2.8 GHz 10 bits digitally controlled oscillator (DCO) for high speed clocking of SoCs. The DCO includes only 269 tuning cells, which is possible thanks to an original algorithm based on weighted combined thermometer code, used for the DCO frequency control. The control circuit of the DCO includes only binary-to-thermometer decoders: that was possible with the proposed technique of virtual extension of number of the DCO ring. It was implemented in 65- nm CMOS technology, with semi-custom layout design allowed to optimize the area on silicon. The design was validated by transistor-level ELDO extracted schematic simulation. Oscillator shows a good linearity in the frequency tunning range, with average power consumption 6mW/GHz with 1.1V supply voltage. Typical phase noise with 1MHz offset and 2GHz carrying frequency is -86.12dBc/Hz.

Summary form only given. Technology advancement not only enables smaller biosensors, health-care monitoring and communication systems, but also reduces their power dissipation.

An online approach to parameter estimation problems based on binary observations is presented in this paper. This recursive identification method relies on a least-mean squares approach which makes it possible to estimate the coefficients of a finite-impulse response system knowing only the system input and the sign of the system output. The impulse response is identified up to a positive multiplicative constant. The role of the regulative coefficient is investigated thanks to simulated data. The proposed method is compared with another online approach: it is shown that the proposed method is competitive with the other one in terms of estimation quality and of calculation complexity.

This paper describes the implementation of a 100 MHz oscillator based on a Lame-mode MEMS resonator polarized with a low dc bias voltage (< 5 V). Under low vacuum, the MEMS resonator exhibits high quality factors up to 60000 ensuring reasonable performance in terms of measured phase noise: −100 dBc/Hz @ 1kHz from carrier. A specific capacitive actuation/detection scheme ensures an active cancellation of the feedthrough capacitances and facilitates the balance by the rack-level sustaining electronics of the equivalent 50 kΩ motional impedance (on resonance) of the 100 MHz resonator.

A new approach for a digital frequency tuning of NEMS-based oscillators in radio frequency (RF) applications is described. It is based on the modal control of mechanically coupled nanoelectromechanical systems (NEMS) array for which the collective behavior is described by discrete modal analysis. By controlling the electrodes bias voltages distribution, the different transduction gains of the array are adjusted proportionally to specific modal vectors making the whole system operate as one single resonator on the corresponding mode which allows tuning the global oscillator frequency in a large frequency range depending on the coupling stiffness and the resonators number. Besides, by collecting the projected outputs in a common load, the power handling ability of the whole device is raised in all channels improving the phase noise performance of the oscillator.

This paper presents an inductive telemetry platform system for the continuous, real-time and simultaneous remote measurement in harsh environment. First, a SOL (self-oscillating loop) topology for the remote interrogation of wireless battery-less passive sensors is described. This system uses a capacitive sensor configured as an LC-tank whose resonant frequency shifts with the physical measurement. Such a system is generally based on an impedance analyzer in order to measure this frequency shift. In fact, if you increase the distance between the sensor and the reader, the sensibility is not sufficient to use the SOL technique. To overcome this issue, an anti-resonance cancellation, realized with a simple RC cell, is implemented. However, this architecture is dedicated only for a single capacitive sensor. Second, based on an efficient algorithm used for system identification purpose, a readout unit for multiple sensors is proposed. The overall performances of these architectures are analyzed with respect to coupling factor and sensor parameters. Using these two approaches, tests show promising results at mutual coil distances up to 5 cm.

In the field of resonant nano-electro-mechanical system (NEMS) design, it is a common misconception that large-amplitude motion, and thus large signal-to-noise ratio, can only be achieved at the risk of oscillator instability. In the present paper, we show that very simple closed-loop control schemes can be used to achieve stable large-amplitude motion of a resonant structure even when jump resonance (caused by electrostatic softening or Duffing hardening) is present in its frequency response. We focus on the case of a resonant accelerometer sensing cell, consisting of a nonlinear clamped-clamped beam with electrostatic actuation and detection, maintained in an oscillation state with pulses of electrostatic force that are delivered whenever the detected signal (the position of the beam) crosses zero. We show that the proposed feedback scheme ensures the stability of the motion of the beam much beyond the critical Duffing amplitude and that, if the parameters of the beam are correctly chosen, one can achieve almost full-gap travel range without incurring electrostatic pull-in. These results are illustrated and validated with transient simulations of the nonlinear closed-loop system.

International audience; A novel tuning strategy of nanoelectromechanical systems (NEMS)-based filters is proposed based on the modal control of mechanically coupled NEMS arrays. This is done by adjusting separately addressed distributed actuation and detection configurations proportionally to desired modal vectors. This control scheme enhances the global output signal, raising the power handling of the filter on all channels. Although the modal control of 1-D arrays exhibits narrow-band responses with adjustable resonance frequency, its application to 2-D arrays produces filters with both adjustable bandwidth and central frequency. One possible realization scheme is suggested by using electrostatically driven coupled NEMS arrays whose transduction gains are adjusted by changing the electrodes' bias voltages. Dispersion effects on both 1-D array and 2-D array frequency response are analytically expressed using eigenvalues perturbation theory. Based on these results, we show how to reduce their impact by appropriately choosing the coupling stiffness and the number of resonators.

We present a new approach to parameter estimation problems based on binary measurements, motivated by the need to add integrated low-cost self-test features to microfabricated devices. This approach is based on the use of original weighted least-squares criteria: as opposed to other existing methods, it requires no dithering signal and it does not rely on an approximation of the quantizer. In this technical note, we focus on a simple choice for the weights and establish some asymptotical properties of the corresponding criterion. To achieve this, the assumption that the quantizer's input is Gaussian and centered is made. In this context, we prove that the proposed criterion is locally convex and that it is possible to use a simple gradient descent to find a consistent estimate of the unknown system parameters, regardless of the presence of measurement noise at the quantizer's input.

A robust control scheme for dynamic resonance frequency tracking in NEMS resonant mass sensors arrays is described. This is accomplished using a simple measurement set-up that can be integrated to the sensor altering the frequency resolution and enhancing the performance and the robustness to the parameters dispersion effect and to the global model uncertainty. It is based on a PLL oscillating loop in which the VCO generates the common excitation of the whole array and the feedback signal is given by the collected array's output. The measurement issue is turned to a servo-control problem that maintains the phase shift between the drive signal and the output's one at − π/2 that occurs on resonance, adjusting the VCO frequency to the sensor's variant resonance frequency. The controller is designed using H∞ loop-shaping method, rejects the disturbance described by the resonance frequency shift with a large bandwidth, attenuates the phase noise and guarantees good stability margins. The VCO control voltage shows an image of the amount of change in the resonance frequency surpassing the need of additional hardware components and external measurement circuitries.

In this paper, we describe a robust control law for distributed PLL network using H∞ optimization problem. The controller can be uniformly applied on all distributed nodes and guarantees good stability margins, enhanced performance and reduced jitter noise. A 2-dimensional Cartesian mesh network structure is considered without using any feedback loop phase information propagation to eliminate undesirable mode-locked states.

This paper reviews some recent advances related to NEMS based on top-down technologies: from stand-alone NEMS to VLSI NEMS and NEMS-CMOS integration.

International audience; Because of its moderate cost in terms of electronics, resonant sensing has become commonplace in the context of MEMS and NEMS devices. It is usual to drive such resonators below the critical open-loop Duffing amplitude, above which the oscillations become unstable. However, when scaling sensors down to NEMS, nonlinearities may occur at very low amplitudes, making oscillations very difficult to detect. This paper describes a very general way to compute the critical amplitude in open-loop operation for beam resonators, before it focuses on closed-loop Duffing-type resonators. The major contribution of this paper is the use of describing function analysis validated by numerical simulations to show that it is possible to obtain stable oscillations with amplitudes much larger than the critical Duffing amplitude. As a practical consequence, the measured currents are significantly increased and the constraints on the sensing electronics can be relaxed.

A simple dynamic detection of the resonance frequency shift in NEMS resonant mass sensors is described. This is done without the use of an external frequency sweep signal nor a frequency counter limiting the dynamic variation detection. Neither an amplitude control nor a phase switcher is required for maintaining the resonant oscillations. The sensor is driven directly by the VCOpsilas output for which the control signal is calculated by a robust Hinfin controller using loop-shaping method. Only the sensor and the VCOpsilas signals signs are detected and compared so that the controller regulates the phase difference between them, maintaining it at pi/2 which occurs on resonance frequency. The measurement issue is transformed to a novel control problem that rejects the disturbance described by the resonance frequency shift, attenuates the phase noise and guarantees good stability margins.

The first front-end CMOS co-integration based on the lateral SGMOSFET presented in this paper demonstrates the benefit of a co-integration approach for NEMS devices. Performance using this device is compared to that obtained with a standalone ASIC. The next step will consist of replacing equivalently the input transistor of the ASIC cascode structure by the SGMOSFET.