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A simple reference field-effect transistor (REFET) for pH detection in differential mode measurements is described. The device is based on a pH-insensitive polymeric PVC membrane cast on the gate insulator of an ion-sensitive field-effect transistor (ISFET) device, that has been previously silylated. The REFET shows low pH sensitivity (1.8 mV/pH) and is only slightly affected by the concentration of Na + and K + . The pH response of a combined solid-state device consisting on a pH ISFET (of 45 mV/pH sensitivity), the REFET and a quasi-reference electrode (QRE) (Pt) is 43.7 mV/pH from pH 2 to 9.

The fabrication of pH-sensitive ISFET devices in an unmodified two-metal commercial CMOS technology (1.0 um from Atmel-ES2) is reported. The ISFET devices have a gate structure compatible with the CMOS process, with an electrically floating electrode consisting on polysilicon plus the two metals. The passivation oxynitride layer acts as the pH-sensitive material in contact with the liquid solution. The devices have shown good operating characteristics, with a 47 mV/pH response. The use of a commercial CMOS process allows the straightforward integration of signal-processing circuitry. An ISFET amplifier circuit has been integrated with the ISFET sensors.

A hydrodynamical model calculation that includes retardation, nonlocal effects within the constitutive equation as well as damping through a constant parameter, has been used to interpret the surface photoemission results for simple metals. Special attention has been paid to the effects that multipole surface modes have in the spectrum. The photon field is screened by the electron gas modeling the vacuum–metal interface with a low density overlayer. A constant initial state for the electron at the Fermi level is assumed. We conclude that the main structure of the photoemission spectrum, a peak at ω0p, is not produced by the generation of multipole modes, and instead these modes produce a secondary structure between ω0 and ωp whose number and position depend on the electronic profile.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. (CC BY-NC-ND 3.0)., We present the magnetic characterization of cobalt wires grown by focused electron beam-induced deposition (FEBID) and studied using static piezoresistive cantilever magnetometry. We have used previously developed high force sensitive submicron-thick silicon piezoresistive cantilevers. High quality polycrystalline cobalt microwires have been grown by FEBID onto the free end of the cantilevers using dual beam equipment. In the presence of an external magnetic field, the magnetic cobalt wires become magnetized, which leads to the magnetic field dependent static deflection of the cantilevers. We show that the piezoresistive signal from the cantilevers, corresponding to a maximum force of about 1 nN, can be measured as a function of the applied magnetic field with a good signal to noise ratio at room temperature. The results highlight the flexibility of the FEBID technique for the growth of magnetic structures on specific substrates, in this case piezoresistive cantilevers, This work was supported by the Spanish Ministry of Economy and Competitiveness through projects No. TEC2011-23600, Nanoselect-CSD2007-00041 (Consolider-Ingenio 2010 programme) and MAT2011- 27553-C02, including FEDER funds, by the Aragón Regional Government, and by the EU Sudoe Interreg TRAIN2 proyect.

Pressure sensors and aceelerometer structures have been fabricated in a commercial CMOS foundry technology (1.0 µm from Atmel-ES2) using a post-processing for back-side wafer micromachining. The overall technology (CMOS plus post-processing) can be used for integrated sensor system design through a specific design kit in the standard foundry design environment. Fabrication is then performed so that postprocessing is transparent to the user.

Highly sensitive sensors are one of the enabling technologies for the biomarker detection in early stage diagnosis of pathologies. We have developed a self-sensing nanomechanical force probe able for detecting the unbinding of single couples of biomolecular partners in nearly physiological conditions. The embedding of a piezoresistive transducer into a nanomechanical cantilever enabled high force measurement capability with sub 10-pN resolution. Here, we present the design, microfabrication, optimization, and complete characterization of the sensor. The exceptional electromechanical performance obtained allowed us to detect biorecognition specific events underlying the biotin-avidin complex formation, by integrating the sensor in a commercial atomic force microscope., This work has been supported by the Spanish Ministry of Science and Innovation through projects NANOSELECT-CSD2007-00041(Consolider-Ingenio 2010) and TEC2011-23600, by the European Union through the COST ACTION TD1002 and partly supported by the PRIN-MIUR Project No. 2009 WPZM4S and by AIRC (Grant IG10412.)

We have developed self-sensing piezoresistive microcantilevers optimized for the measurement of (biomolecular) forces. Typical dimensions are 250 μm in length, 8-20 μm in width and 450 nm in thickness, with spring constants of about 1 mN/m. The devices have been electromechanically tested on wafer and show good force resolutions in air between 35 and 130 pN depending on the cantilever dimensions. We have also tested the electromechanical behavior of the cantilevers in liquid environment and we show that both the force sensitivity and the noise characteristics of the devices are not noticeably degraded as compared with their response in air. This opens the way to the use of the cantilevers in single molecule force spectroscopy of biomolecules.

A new dithiamacrocycle incorporating a phosphine donor group (I) has been synthesized and tested as neutral carrier in PVC membranes. ClO−4-selective CHEMFET and ISE devices based on these plasticized membranes have been developed. Both devices have shown Nernstian response and a wide working pH range. Most common anions, except BF−4, do not cause interferences. The response properties and selectivity found for perchlorate ions compare favourably with the commercial and conventional ClO−4 electrodes based on quaternary ammonium ion-exchange sites. This is probably the first example of perchlorate selective CHEMFETs.

Silver(I)-selective CHEMFET devices based on plasticized membranes have been developed. It has recently been shown by the authors that simple molecules containing a thioether group are good Ag + sensing molecules. In this work the monothioether diphenyl sulfide PhSPh molecule has been used as the sensing ionophore for silver CHEMFETs. The devices have shown a Nernstian response, good selectivity coefficients for interfering ions and linear responses over three decades of silver activity.

International audience; In this present study, we have analyzed one cytokine biomarker; interleukin-10 (IL-10), which is one of many antigens that is secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). Therefore, a biosensor was developed in order to increase the sensitivity of detection, decrease the time of measurements, and to simultaneously detect varying cytokine biomarkers using eight gold working electrodes (WE). This biosensor was fabricated onto a polyimide (PI) substrate using soft lithography technique. The anti-human IL-10 monoclonal antibodies (mAb) were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium. Cyclic voltammetry (CV) was applied during the microelectrode fabrication process to characterize the gold microelectrode surface properties, while, electrochemical impedance spectroscopy (EIS) characterized the diazonium modification made on the gold microelectrodes, followed by the immobilization of IL-10 mAb. Here, a variation of the change transfer resistance (Rct) has confirmed that diazonium has modified the gold microelectrodes and that the mAb was successfully covalently bonded onto the surface.

International audience; This paper describes a simple technique for the fabrication of a gold microelectrode array with an integrated Ag/AgCl reference microelectrode based on polyimide (PI) which is a flexible and biocompatible thermoplastic substrate. The investigated fabrication technology was based on soft lithography which involved a combination of replica molding (RM) and patterning of self-assembled monolayers (SAMs), through microcontact printing (μCP). From a fabricated silicon microelectrode mold, an elastomeric stamp of the microelectrodes was replicated in polydimethylsiloxane (PDMS) and inked with octadecanethiol (ODT) for patterning of the gold surface. The non-patterned gold was then removed by selective chemical etching leaving very well defined gold microelectrodes with a high resolution. Finally, the integrated Ag/AgCl reference microelectrode was fabricated by silver electro-deposition onto the gold microelectrode. The developed biosensor was then tested for a medical application by immobilizing both monoclonal antibodies (mAb); anti-human interleukin-10 (IL-10) and anti-human tumor necrosis factor-alpha (TNF-α) onto different working electrodes. Functionalization of the gold microelectrodes was made with carboxyl diazonium through cyclic voltammetry (CV). The multiple detection of the corresponding cytokines was verified by fluorescence, whilst electrochemical impedance spectroscopy (EIS) analysis quantified a detectable IL-10 cytokine concentration from 1 to 15 pg/mL. This confirmed the biorecognition between the anti-human mAb (IL-10 and TNF-α) and of its corresponding cytokine. The obtained results show that the mAb's were efficiently immobilized and the proteins for human IL-10 were detectable at weak concentrations. The electrochemical measurements were applied on the manufactured gold microelectrodes for ∼9 h. This shows a high resistance of the microelectrodes for long-lasting measurements and, therefore, highlights the good adhesion of gold-PI. The results presented here have demonstrated the feasibility of a simple microelectrode fabrication technology with application to a biomedical response.

In this work we present the development of a new set-up that allows on-wafer sensitivity characterization of piezoresistive cantilevers. In this way we reduce considerably the testing time compared to the techniques available up to date but at the same time we maintain a high measurement precision. Moreover it can be easily used for characterization of broad types of batch fabricated micro- and nanoelectromechanical systems (MEMS and NEMS). Together with the sensitivity measurement we present also the methods to test the cantilever spring constant and the electrical noise. Using these techniques we measured the performance of multiple piezoresistive cantilevers in two wafers and from these values we extracted important fabrication materials parameters such as Young modulus, Hooge and piezoresistive factors. © 2012 IEEE.

Validation of a technological process requires an intensive characterization of the performance of the resulting devices, circuits or systems. The technology for the fabrication of Micro and Nanoelectromechanical systems is evolving rapidly, with new kind of device concepts for applications like sensing or harvesting are being proposed and demonstrated. However, the characterization tools and methods for these new devices are still nor fully developed. Here, we present an on-wafer, highly precise and rapid characterization method to measure the mechanical, electrical and electromechanical properties of piezoresistive cantilevers. The set-up is based on a combination of probe-card and atomic force microscopy (AFM) technology, it allows accessing many devices across a wafer and it can be applied to a broad range of MEMS and NEMS. Using this set-up we have characterized the performance of multiple submicron thick piezoresistive cantilever force sensors. For the best design we have obtained a force sensitivity RF=158 uV/nN, a noise of 5.8 uV (1Hz-1kHz) and a minimum detectable force (MDF) of 37 pN with a relative standard deviation of sigma=8%. This small value of sigma, together with a high fabrication yield >95%, validates our fabrication technology. The devices are intended to be used as bio-molecular detectors for the measurement of intermolecular forces between ligand and receptor molecule pairs., This work has been supported by MICINN through projects TEC2011-23600 and NANOSELECT-CSD2007- 00041 (Consolider-Ingenio 2010 Programme).

International audience; In this work we report the fabrication and characterization of a label-free impedimetric immunosensor based on a silicon nitride (Si3N4) surface for the specific detection of human serum albumin (HSA) proteins. Silicon nitride provides several advantages compared with other materials commonly used, such as gold, and in particular in solid-state physics for electronic-based biosensors. However, few Si3N4-based biosensors have been developed; the lack of an efficient and direct protocol for the integration of biological elements with silicon-based substrates is still one of its the main drawbacks. Here, we use a direct functionalization method for the direct covalent binding of monoclonal anti-HSA antibodies on an aldehyde-functionalized Si-p/SiO2/Si3N4 structure. This methodology, in contrast with most of the protocols reported in literature, requires less chemical reagents, it is less time-consuming and it does not need any chemical activation. The detection capability of the immunosensor was tested by performing non-faradaic electrochemical impedance spectroscopy (EIS) measurements for the specific detection of HSA proteins. Protein concentrations within the linear range of 10−13-10−7 M were detected, showing a sensitivity of 0.128 Ω μM−1 and a limit of detection of 10−14 M. The specificity of the sensor was also addressed by studying the interferences with a similar protein, bovine serum albumin. The results obtained show that the antibodies were efficiently immobilized and the proteins detected specifically, thus, establishing the basis and the potential applicability of the developed silicon nitride-based immunosensor for the detection of proteins in real and more complex samples. Highlights An impedimetric label-free immunosensor was developed for the specific detection of human serum albumin proteins. Anti-HSA antibodies were covalently immobilized on silicon nitride surfaces using a direct functionalization methodology. Silicon nitride offers multiple advantages compared to other common materials. The proposed sensor has high sensitivity and good selectivity for the detection of HSA proteins.

The results of an innovative training experience carried out over several courses on engineering projects executed by student's teams, giving them a hierarchical organization structure are presented. This yields a stronger capacity for achieving more ambitious objectives and effectiveness. The paper addresses the problems and solutions that this hierarchical structure represents, along with how to implement guidelines for monitoring student's work, mentoring and specific assessment tasks that have been applied to Electronic Engineering projects.

In this paper a scheme of convex corner compensation for etching in aqueous KOH using only strips is presented. Turns and branches are used to control the etching front on the strip surface for better compensation quality. The design rules as well as the effects of turning and branching on the effective compensation length are presented. The etching fronts on the bottom are investigated by experiment. Applications of the new structures are shown.

International audience; Trichloroethylene (TCE), a suspected human carcinogen, is one of the most common volatile groundwater contaminants. Many different methodologies have already been developed for the determination of TCE and its degradation products in water, but most of them are costly, time-consuming and require well-trained operators. In this work, a fast, sensitive and miniaturised whole cell conductometric biosensor was developed for the determination of trichloroethylene. The biosensor assembly was prepared by immobilising Pseudomonas putida F1 bacteria (PpF1) at the surface of gold interdigitated microelectrodes through a three-dimensional alkanethiol self-assembly monolayer/carbon nanotube architecture functionalised with Pseudomonas antibodies. The biosensor response was linear from 0.07 to 100 mu M of TCE (9-13,100 mu g L(-1)). No significant loss of the enzymatic activity was observed after 5 weeks of storage at 4 A degrees C in the M457 pH 7 defined medium (two or three measurements per week). Ninety-two per cent of the initial signal still remained after 7 weeks. The biosensor response to TCE was not significantly affected by cis-1,2-dichloroethylene and vinyl chloride and, in a limited way, by phenol. Toluene was the major interference found. The bacterial biosensor was successfully applied to the determination of TCE in spiked groundwater samples and in six water samples collected in an urban industrial site contaminated with TCE. Gas chromatography-mass spectrometric analysis of these samples confirmed the biosensor measurements.

Measurement of D-dimer has subsequently become an essential element in the diagnostics of deep vein thrombosis and pulmonary embolism; in this context microelectrodes with an area of 9×10(-4) cm(2) were used to develop impedimetric immunosensor for detecting deep venous thrombosis biomarker (D-dimer). The biosensor is based on functionalized carbon nanotubes (SWCNT-COOH) where the antibody (anti-D-dimer) was immobilized by covalent binding. The electrical properties and the morphology of the biolayer were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry and atomic force spectroscopy (AFM). Impedimetric microimmunosensor allows to obtain sensitivity of 40.1 kΩ μM(-1) and detection limit of 0.1 pg/mL (0.53 fM) with linear range from 0.1 pg/mL to 2 μg/mL (0.53 fM to 0.01 μM). We demonstrate that using carbon nanotubes and microelectrodes, high sensitivity and dynamic range were obtained. The biosensor exhibited a short response time of 10 min. Moreover, the studied immunosensor exhibits good reproducibility (R.S.D. 8.2%, n=4).

The implementation of a pH-ISFET and a flow-through sandwich nitrate selective electrode (ISE) as a reference electrode in a flow-injection system for pH determination, is described. With this system, the linear working range extends from pH 1 to 13 with a sensitivity of 59 mV per pH unit and a relative standard deviation of 0.5%. To implement the sensor in the flow system, a special flow assembly which integrates the ISFET and the ISE has been designed.

A high-frequency bidirectional capacitance method has been modified to study the evolution of the density of interface states generated by Fowler-Nordheim tunneling injection. The interface state response during the measurement of the capacitance curves in both directions has been analyzed in detail in order to extend the use of the method to intermediate temperatures. In this way an analytical approximation of the occupation factor through stepwise functions has been obtained, following the evolution of the sample from inversion to accumulation. It has been confirmed that Fowler-Nordheim injection at 77 K does not immediately generate interface states, even in the absence of an intermediate state of positive charge trapping, and that thermal activation is necessary for such states to be produced.

We have fabricated 340 nm thick U-shaped microcantilevers with electrical output to be used as sensors for biomolecular detection, which requires a force resolution better than 100 pN. Piezoresistors or MOS transistors have been used as integrated electromechanical transducers. The devices have been fabricated by N-type doping using As ion implantation to obtain shallow junctions, and have been oriented on the (100) crystallographic direction (45° from the wafer flat) to maximize piezoresistance. Both types of cantilevers have been successfully fabricated. The integrated MOSFETs have shown good conduction characteristics. We report an (amplified) force sensitivity of 60 ?V/pN for piezoresistive cantilevers 250 ?m long and 8 ?m wide.

An optimization of the fabrication technology has been carried out in order to fix the best parameters for ISFET devices. The main parameters taken into account are threshold voltage, which is adjusted by ion implantation and drain and source series resistances by optimizing dose, energy and post annealing processes. SUPREM-3 simulations have been used for this purpose. An electrical model of the ISFET to be included in SPICE simulator has also been developed and permits the determination of the electrical behaviour of the chemical sensor.

Charge trapping and the generation of interface traps in thermally grown SiO2 and its interface with silicon, produced by Fowler–Nordheim tunneling injection at low temperatures from highly doped Si substrates, have been investigated. The results that can be obtained with the constant‐current‐injection method, when a moderate amount of charge is trapped inside the potential barrier, have been analyzed. This has afforded information about the position of the charge trapped in the oxide. No increase in the interface‐trap density has been produced immediately after injection at 77 K, but, as the temperature is raised after injection, the growing of a peak of interface states has been observed. This phenomenon had been reported to be produced as a consequence of a previous hole trapping but, in this case, this intermediate stage of positive‐charge building has not been observed. This effect is discussed, taking into account published models.

The application of ion sensitive field effect transistors (ISFET's) to the measurements of the pH of chemical solutions is one of the most important fields of microelectronic sensors. However, ISFET's still present some problems, such as shifts and drifts of electrical characteristics. In this work a systematic study of the evolution of electrical characteristics of EOS (electrolyte-oxide-semiconductor) and ENOS (electrolyte-nitride-oxide-semiconductor) structures, equivalent to ISFET gates, using the quasi-static C-V method is presented. Results show that the total drift in the flat band voltage can be separated in two terms, one due to immersion in an aqueous ambient and other due to the ionic strength.

High‐energy implantation involves ion velocities such that ions are partially stripped of their electronic charge when moving inside the solid target. Most ion range distribution calculations so far have been using mean charge states as a function of the ion velocity, in order to determine the ion electronic stopping. However, it is known that fluctuations in the ion charge state lead to an increased energy‐loss straggling of the ion beam. In this work the effect of charge‐state fluctuations on ion range distribution calculations is studied. We show that the ion equilibrium charge‐state distributions can be used to account for charge‐state fluctuations inside a Monte‐Carlo formalism, and that this effect can be important in order to understand implanted ion range distributions in the MeV energy range.

International audience; A microspotting tool, consisting of an array of micromachined silicon cantilevers with integrated microfluidic channels is introduced. This spotter, called Bioplume, is able to address on active surfaces and in a time-contact controlled manner picoliter of liquid solutions, leading to arrays of 5 to 20-μm diameter spots. In this paper, this device is used for the successive addressing of liquid solutions at the same location. Prior to exploit this principle in a biological context, it is demonstrated that: (1) a simple wash in water of the microcantilevers is enough to reduce by >96% the cross-contamination between the successive spotted solutions, and (2) the spatial resolution of the Bioplume spotter is high enough to deposit biomolecules at the same location. The methodology is validated through the immobilization of a 35mer oligonucleotide probe on an activated glass slide, showing specific hybridization only with the complementary strand spotted on top of the probe using the same microcantilevers. Similarly, this methodology is also used for the interaction of a protein with its antibody. Finally, a specifically developed external microfluidics cartridge is utilized to allow parallel deposition of three different biomolecules in a single run.

We present two novel methods for the preparation of arbitrary micro-scale patterns of polymers on surfaces with pre-defined topography. While photosensitive polymers are used commonly together with optical lithography, the methods presented can be used for nonphotostructurable polymers and where spin-coating cannot be performed. As demonstrator of the viability of the proposed fabrication process, they have been applied for the definition of hydrophobic barriers on a microfluidics network, which is dedicated to selectively dispense liquid to a spotting device consisting of 12 silicon microcantilevers.

In this paper a multichip module system for automotive applications is described. The MCM substrate is a IMS (Isolated Metal Substrate), which has been used for integration of analog signal processing stages, complex logic circuits and even power switching transistors. The main functionality of the door module implemented with this MCM, is the control of the power window motor with antipinch feature, although the prototype has been completed with communication (LIN-bus).

This paper reports the development of piezoresistive microcantilevers for the detection of biomolecules by the measurement of intermolecular binding forces. The detection of the small forces involved in molecular recognition (

We describe the characterization of a novel copper-sensitive polymeric membrane and the electrochemical response of electrolyte-membrane-insulator-semiconductor structures. The membrane has shown a Nernstian response towards Cu(II) ions in electrodes.

Planar sodium-selective potentiometric microelectrodes with a conducting polymer (polypyrrole doped with cobaltabis(dicarbollide) ions ([3,3′-Co(1,2-C 2 B 9 H 11 ) 2 ] − )) as solid contact layer between the polymeric sensitive membrane and the platinum substrate have been constructed. The p-tert- butylcalix[4]arene ethyl ester was used as ionophore for sodium recognition. The microelectrode shows a linear response for Na + concentrations between 3.0 × 10 −6 and 1.0 × 10 −1 M with a Nernstian slope of 58.65 ± 2 mV per decade and a detection limit of 1.45 × 10 −6 M. The response time was 14 s, and the electrode is suitable for use within the pH range of 3–10.

The animal olfactory system represents the gold standard of olfactory biosensors with its capability to identify and discriminate thousands of odorant compounds. In order to mimic the performances of natural olfactory sensors it is necessary to develop methods and techniques for the production, immobilization and electrical characterization of olfactory receptors. We review in this paper some of the advances we obtained in these fields. (c) 2006 Elsevier B.V. All rights reserved.

The development of novel potassium-ion selective microelectrodes using microfabrication technologies and electrochemical polymerization is described. The microelectrode is based on electropolymerized polypyrrole films, doped with cobaltabis(dicarbollide) ions ([3,3′-Co(1,2-C 2 B 9 H 11 ) 2 ]), as an internal solid contact layer between the platinum surface and the polymeric sensing membrane. The ion selective membranes, which are based on a plasticized PVC membrane, contain 1,3-(di-4-oxabutanol)-calix[4]arene-crown-5 as a novel potassium ionophore, and are deposited on top of a layer of the conducting PPy[3,3′-Co(1,2-C 2 B 9 H 11 ) 2 ]. The response of the microelectrode was linear with a Nernstian slope of 51 ± 2 mV decade −1 over a K + ion concentration range of 6 × 10 −6 to 1 × 10 −1 M, with a detection limit of 1.8 × 10 −6 M. The microelectrode is suitable for use within the pH range of 3–11. The electrode could be used for at least one month without a considerable alteration in its potential.

Silicon integrated RF passive components performed using standard CMOS processes and silicon micromachining post-processing are studied. The results indicate that the removal of the Si substrate under the components using micromachining technology is a very suitable procedure to improve their electrical performance. The self-resonant frequency and maximum quality factor of the inductors are increased by a factor about three. Similar results are obtained for interdigitized capacitors.

We present the fabrication of cell-based biosensors with cell positioning capabilities, which contain ion-sensitive field-effect transistors (ISFETs) and integrated dielectrophoresis electrodes. Yeast cells and bacteria have been successfully positioned on the active area of the device. The ISFETs have shown good operating characteristics as pH sensors.

We describe the development of polycrystalline silicon piezoresistive micro/nanocantilevers for the measurement of intermolecular forces in biochemical sensing. The cantilevers have been fabricated both in a dedicated technology and in a commercial CMOS technology with an additional micromachining postprocessing. The sensitivity and resolution required by the application are achieved with cantilevers with submicrometer thickness and width in the micrometer range. The cantilevers have been successfully tested by applying a known displacement with an AFM, obtaining a value of 12 for the gauge factor.

International audience; Langmuir-Blodgett (LB) technique appears to be quite suitable for generating biospecific surfaces and it has potential application for fabricating biosensors. In this work, mixed Langmuir-Blodgett films of immunoglobulin G/amphiphile have been transferred onto hydrophobic silver surface previously modified by I-octadecanethiol (ODT) SAMs. In order to obtain stable LB films, the influences of different parameters - type of amphiphile, surface pressure and pH - on the properties of mixed IgG/amphiphile monolayer. were investigated. Electrochemical properties of the engineered immunosensor have been measured by impedimetric spectroscopy. The immunosensor obtained exhibits a high sensitivity and a good specificity in a linear dynamic range from 200 to 1000 ng ml(-1). (C) 2004 Elsevier B.V. All rights reserved.

In this paper a multichip module system for automotive applications is described. The use of microsystems in automotive industry allows size reduction of electronic units and also a reduction in its cost. The presented microsystem is based on a IMS (Isolated Metal Substrate) substrate, which has been used for integration of analog signal processing stages, complex logic circuits, sensors and even power transistors. The functionality of the microsystem is the control of a power window motor with antipinch feature. The system architecture is based on a single microcontroller and a multipurpose ASIC. The trapping detection strategy is based on current sensing and signal processing.

In this paper a multichip module system for automotive applications is described. The MCM substrate is a IMS (isolated metal substrate), which has been used for integration of analog signal processing stages, complex logic circuits and even power transistors. The functionality of the door module implemented with this MCM, is the control of the power window motor with antipinch feature. A prototype that also includes central lock control, courtesy light control and drivers for communication of the module to the rest of the vehicle electronic systems has been completed.

This work presents a new circuit for the conversion of Binary Phase Shift Keying signals (BPSK) into Amplitude Shift Keying signals (ASK). The basic principles of the conversion method are the super harmonic injection of oscillator circuits and interference phenomena. The first one is used to synchronize the oscillators while the second is used to generate an amplitude interference pattern that reproduces the original phase modulation. When combined with an envelope detector, the proposed circuit allows the coherent demodulation of BPSK signals without the need of a carrier recovery system. Two prototypes of the converter have been implemented. The first one is a hybrid version working in the 300-400 MHz frequency range. The second has been implemented using Multi Chip Module (MCM) technology, and is intended for working in the range of 1.8-2.0 GHz. The time response of the converter to phase changes of the input signal is about 100 ns for the hybrid version and scales down to about 15 ns for the MCM version, giving upper limits for the modulation rate of about 5 Mbit/s and 30 Mbit/s, respectively.

FTIR (Fourier-transform infrared) spectroscopy was used to analyze polysilicon-oxide-silicon structures. The results obtained show that this technique is adequate for measuring induced stress produced by technological processes in micromechanics. Variations were observed in the absorption peak of the oxide among different samples depending on the technological characteristics. X-ray diffraction was also used to analyze the state of stress in the polysilicon layer. The two kinds of measurements are clearly correlated. >

Nowadays, handling of biological objects at the single-cell level is one of the most active and important research fields. To achieve this goal dimensions of the required tools must roughly match those of the bioparticles at issue, usually ranging from 1 to 100 /spl mu/m. The objective of this paper consists of presenting a microsystem designed for particle microhandling. Some results with polystyrene microspheres are also presented. The operating principle of the aforementioned microsystem hinges upon dielectrophoresis (DEP), which is defined as the lateral motion of electrically neutral matter under the influence of non-uniform electric fields. In practice, the device was fabricated on a silicon substrate onto which interdigitated castellated microelectrodes made of platinum were patterned by lift-off. Moreover, the substrate was micromachined utilising TMAH to anisotropically etch the silicon wafer. Microchamber walls were patterned by PDMS, a photocurable resin which allows a constant sample volume when performing the experiments.

An integrated chemical sensor with multiple ion and temperature sensors, composed of two ISFETs (pH and K/sup +/), one platinum pseudo-reference electrode and temperature sensor based on a platinum resistor has been realised by using a CMOS-compatible technology and silicon micromachining. This paper describes a summary of the fabrication process and results of the device characterisation in vitro. The feasibility of the fabrication technology has been demonstrated and all devices have operated satisfactory, with a response showing good sensitivity and linearity. This multisensor will be used in the on-line early detection of myocardial ischemia during cardiac surgery while the heart is artificially arrested (extracorporeal circulation).

Describes the development, packaging and characterization of a silicon-based impedance microprobe for myocardial ischemia monitoring during open-heart surgery. The microprobe consists of four planar Pt electrodes micromachined on an isolated silicon substrate. The microprobe has been assembled on a ceramic substrate, packaged with epoxy resin and wired to the external instrumentation. Mechanical characterization of the system and in vitro biocompatibility tests of the device have been performed. Measurement instrumentation for preliminary tests has also been developed.

Boron implantation on polysilicon films changes the residual stress value and its evolution against the annealing temperature. The films deposited at 590 degrees C present a marked columnar structure, being less important in the implanted samples. However, the X-ray diffraction texture is still mostly determined by the deposition temperature, the implantation process having only a small effect. It has also been found that the implantation process favours grain growth parallel to the surface layer while the perpendicular size remains basically unaltered.

Design verification methodologies and tool such as DRC and ERC used on MEMS design have been inherited from the transistor based analog and digital full custom design flows. However the devices are defined on a 2D layout, they have a 3D structure. Thus, current tools do not have into account the new features that appear in MEMS design, especially those related with device micro machining. The main consequence on it is that it is necessary to include information of the vertical parameters on the DRC, what is not at all usual in classical design. We claim that the inclusion of such information together with the consequent improvement of tools for DRC, ERC and device parameter extraction, can reduce design and simulation efforts as well as improve the manufacturing yield.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when applied to inductors in which the fabrication process includes integration substrate removal. However, it is also applicable to inductors on low-loss substrates. The method optimizes the width of the metal strip for each turn of the inductor coil, leading to a variable strip-width layout. The optimization procedure has been successfully applied to the design of square spiral inductors in a silicon-based multichip-module technology, complemented with silicon micromachining postprocessing. The obtained experimental results corroborate the validity of the proposed method. A Q factor of about 17 have been obtained for a 35-nH inductor at 1.5 GHz, with Q values higher than 40 predicted for a 20-nH inductor working at 3.5 GHz. The latter is up to a 60% better than the best results for a single strip-width inductor working at the same frequency.

SIXE (Spanish Italian X-ray Experiment) is an X-ray detector with geometric area of 2300 cm2, formed by four identical gas-filled Multicell Proportional Counters, and devoted to study the long term spectroscopy of selected X-ray sources in the energy range 3–50 keV. The main characteristics of SIXE are: time accuracy of 1 microsecond, spectral resolution of 5% for E>35 keV and 46/E% for E

A previous two-step hydrodynamic model calculation of angle-resolved photoemission has been improved by modeling the surface with a soft analytic function. The same ground-state potential is used to screen the photon field and to calculate the electronic wave functions. The implemented code can be used for arbitrary ground state densities along the perpendicular direction. Mathematical and physical aspects of the model are discussed extensively. The behavior of the main peak of the spectrum in response to the variation of some parameters leads us to the conclusion that the peak cannot be interpreted as the direct excitation of multipole modes. This conclusion was suggested in the previous two-step model calculation., Comment: 27 pages, 7 figures Accepted for Publication in Surface Review and Letters, Vol 7., No.3 (2000), 1-13