By Topic

Advances in sensors and Interfaces, 2009. IWASI 2009. 3rd International Workshop on

Date 25-26 June 2009

Filter Results

Displaying Results 1 - 25 of 48
  • [Copyright notice]

    Page(s): I
    Save to Project icon | Request Permissions | PDF file iconPDF (41 KB)  
    Freely Available from IEEE
  • Table of contents

    Page(s): II - V
    Save to Project icon | Request Permissions | PDF file iconPDF (74 KB)  
    Freely Available from IEEE
  • Foreword

    Page(s): IX
    Save to Project icon | Request Permissions | PDF file iconPDF (46 KB)  
    Freely Available from IEEE
  • Organizing Committee

    Page(s): X
    Save to Project icon | Request Permissions | PDF file iconPDF (30 KB)  
    Freely Available from IEEE
  • Aware and smart environments: The Casattenta project

    Page(s): 2 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1223 KB) |  | HTML iconHTML  

    ldquoCasattentardquo (Aware home, in Italian) is the demonstrator of a research project on ldquoambient intelligencerdquo, ldquosensor fusionrdquo and ldquowireless sensor networksrdquo. The result is a system composed of fixed and wearable sensor nodes, providing elderly people living alone in their house (but also persons in other situations and environments) with adequate and non intrusive monitoring in order to improve the quality of their life. The system consists of fixed smart sensors distributed in the environment and wearable ones monitoring inhabitants health and activity. The interaction between fixed and mobile nodes, based on the ZigBee wireless protocol, allows indoor tracking and identification of dangerous events. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High-density microelectrode array in CMOS technology applied to acute brain slice recordings and to gene-function studies

    Page(s): 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (53 KB)  

    Microfabrication techniques and, in particular, CMOS technology are very powerful tools to devise bioelectronic and multielectrode microsystems. CMOS-based, fully integrated microelectrode arrays for bidirectional communication (stimulation and recording) with electrogenic cells are presented. These complex microsystems with integrated filter and amplification stages feature a high electrode density (3'150 electrodes per mm2) as well as low noise levels (3-7 muVrms) in the recorded signals and are capable of monitoring relevant electrophysiological responses of cells to electrical stimuli or to pharmacological agents with prospective applications in the fields of neuroscience or pharmascreening. Results from two exemplary applications are shown. In the first one, the system was used to record the electrical activity of cardiomyocytes. To modulate their electrogenic properties lentivirus-derived particles were selected to regulate the bone morphogenetic protein-2 gene expression. This provides a tool for gene-function studies and for the discovery and preclinical evaluation of novel genes with potential therapeutic effects. In the second application acute sagittal cerebellar slices have been used to assess the performance of the device and to demonstrate its potential for application in the field of neuroscience. Subcellular resolution could be demonstrated and spike sorting allowed for analysing the measured action potentials from single neurons. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New probe immobilizations by lipoate-diethalonamines or ethylene-glycol molecules for capacitance DNA chip

    Page(s): 9 - 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (523 KB) |  | HTML iconHTML  

    Label-free DNA detection is of crucial role to when developing point-of-care biochips to be used in personalized therapy. Capacitance detection is a promising technology for label-free DNA detection. However, data published in literature often show evident time drift, large standard deviation, scattered data points, and poor reproducibility. To solve these problems, alkanethiol molecules such as mercapto-hexanol are usually considered as blocking agents. The aim of the present paper is to investigate new blocking agents to further improve DNA probe surfaces. Data from AFM, SPR, fluorescence microscopy, and capacitance measurements are used to demonstrate the new lipoates molecules. Moreover precursor layers obtained by using Ethylene-glycol alkanethiols offer further improvements in terms of diminished detection errors. Film structure is investigated at the nano-scale to justify the detection improvements in terms of probe surface quality. This study demonstrates the superiority of lipoate and Ethylene-glycol molecules as blocking candidates when immobilizing molecular probes onto spot surfaces in label-free DNA biochip. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Amorphous silicon balanced photodiode for application in biomolecular analysis

    Page(s): 15 - 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (925 KB) |  | HTML iconHTML  

    In this work we present an amorphous silicon/amorphous silicon carbide balanced photodiode structure suitable for differential photocurrent measurements in the ultraviolet (UV) and visible range. The device is a three-terminal structure constituted by two series-connected amorphous silicon p-i-n photodiodes. The structure takes advantage of the differential measurement to reveal very small variations of photocurrent in a large background current signal. Application of the device in detection of biomolecules based on the use of photosensors, can allow the increase of both the dynamic range and the sensitivity of the measurement. Several balanced structures with different geometries have been fabricated utilizing a four mask-step process. The devices have been characterized by measuring the common mode rejection ratio as a function of radiation intensity and wavelength and of bias voltage. Experimental results demonstrated that in dark condition differential currents three orders of magnitude lower than the current of each sensor are detected, while under ultraviolet illumination CMRR values around 40 dB have been achieved independent on the bias voltage. These performances are comparable with those obtained by crystalline differential photodiode structures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Gold nanowires: Deposition, characterization and application to the Mass Spectrometry detection of low-molecular weight analytes

    Page(s): 20 - 24
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (670 KB) |  | HTML iconHTML  

    Nanowire fabrication methods are usually classified either as dasiatop downpsila, including for example photo- or electron beam-lithography, or dasiabottom uppsila, involving the synthesis of nanowires from smaller precursors. Lithographically patterned nanowire electrodeposition (LPNE) combines the attributes of the photolithography approach with the versatility of bottom-up electrodeposition methods. In the present study, gold nanowires (Au-NWs) have been electrodeposited using LPNE. The nanomaterials have been then subjected to a spectroscopic and morphological characterization by means of X-Ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). Finally, Au-NWs have been successfully used as desorption/ionization promoters for the Laser-Induced Desorption-Ionization Mass Spectrometry (LDI-MS) detection of low-molecular weight analytes, such as amino acids and peptides. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A nanobiosensor based on olfactory receptors

    Page(s): 25 - 28
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (682 KB) |  | HTML iconHTML  

    We propose an electronic nose of new generation, i.e. a nanosensor based on the use of large biomolecules, olfactory receptors, as sensing material. Modelling, design and experiments performed for proving the concept are reported and discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Large area hybrid detector technology based on amorphous silicon photosensors

    Page(s): 30 - 34
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (723 KB) |  | HTML iconHTML  

    A technological approach for the fabrication of large area hybrid detectors is presented. The proposed hybrid detector consists in an array of hydrogenated amorphous silicon photodiodes directly connected to a CMOS readout chip, which is vertically integrated over the sensor array using flip-chip bonding. In particular, the proposed solution relies on a stack of interconnection layers, deposited on top of the photodiode array, to route each individual pixel output to a separate pre-amplifier channel. This avoids the need for a geometrical matching between the sensor array and the chip contact pads. As a consequence, conventiona non-pixelated readout chip can be used and easy-scalable large area detectors can be produced. Furthermore the sensor array and the readout chip can be optimized independently leading to additional advantages as fast readout, implementation of in-pixel signal conditioning and pre-processing and superior noise performances. Experimental results validating all the technological steps involved in the fabrication of the hybrid detector are reported in detail. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 3D architecture and replaceable layers for label-free DNA biochips

    Page(s): 35 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (431 KB) |  | HTML iconHTML  

    Recent advances in bio-sensing technologies have led to design of bio-sensor arrays for rapid identification and quantification of various biological agents such as drugs, gene expressions, proteins, cholesterol, fats, etc. Various dedicated sensing arrays are already available commercially to monitor some of these compounds in a sample. However, monitoring the simultaneous presence of multiple agents in a sample is still a challenging task. Multiple agents may often attach to the same probes on an array which makes it difficult to design a chip that can distinguish such agents (leading to low specificity). Thus, sophisticated algorithms for targets identification need to be implemented in biochip in order to maximize the number of distinguishable targets in the samples. The proposed algorithms are also required to introduce sophisticated signal processing and more intelligence on-chip. Dealing with these new processing and information technology demands constraints also require more innovative approaches towards hybrid integration technologies. To address such new demands, we discuss in this paper an innovative 3D-integrated bio-chips especially dedicated to label-free DNA detection. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characterization and modelling of SnO2 nanowire sensors for CO detection

    Page(s): 41 - 45
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (703 KB) |  | HTML iconHTML  

    This paper concerns the characterization and modelling of single crystalline tin oxide nanowires used as CO sensors. In this work we analyze the performance of these devices when they are used with variable operating temperatures. The aim is reducing the power consumption and establishing a model suitable for the development of sensing systems working with programmed temperature protocols. In particular we developed and tested a model for the dynamic behaviour of the sensor able to predict the sensor response during transients. This model can be therefore exploited for the selection of optimum temperature profiles targeted to specific applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Photoacoustic trace gas sensing with mid-IR quantum cascade lasers

    Page(s): 46 - 50
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1232 KB) |  | HTML iconHTML  

    We report on the realization of an optoacoustic sensor based on mid-infrared quantum-cascade lasers (QCLs) for the detection of nitric oxide (NO) and formaldehyde (CH2O). A resonant photoacoustic cell equipped with 4 electret microphones was excited in its first longitudinal mode by the modulated laser light. A detection limit of 150 parts in 109 (ppbv) for NO and CH2O was found, using distributed feedback QCLs operating in pulsed mode at 5.34 mum and 5.62 mum, respectively. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Progress in micro-pattern gaseous detectors and their applications

    Page(s): 52 - 57
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1790 KB) |  | HTML iconHTML  

    In the last decade, several new imaging gaseous detectors, called ldquomicro-pattern gaseous detectorsrdquo, have been conceived and rapidly developed. In this paper, the most popular designs of these detectors and their applications to high energy physics and astrophysics experiments will be described. The main focus of this review will however be on the ongoing activities on practical applications of micro-pattern detectors to medicine and industry. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nano-materials and nano-technologies for novel photon detection systems

    Page(s): 58 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1798 KB) |  | HTML iconHTML  

    The transition from macro to micro-sensor systems in the last decades has been made possible by the use of silicon and by development of micro-technology. Semiconductors opened the door to the realization of sensors based on Very Large Scale Integration Systems in which the external information is transduced into an electrical signal managed directly inside the micro-devices by the use of microelectronics. Up to now, the most powerful integrated systems may be considered the Medipix chip for medical imaging and avalanche photodiodes operated in Geiger mode (SiPMs) for photon radiation detection. A similar transition from micro to nano is now knocking at the door. New nanotechnologies allow the realization of finely pixelled surfaces and manipulation of nano- structured materials at a few nanometer scales. Sensors can be created by flipping from a top-down process to a bottom-up approach. To do this, one must develop new materials having similar electrical properties of silicon but chemical properties appropriates for a bottom-up building process. Among the wide variety of materials which can be managed with nano-technological processes, Carbon Nanotubes (CNT) dominate for their unique mechanical and electrical characteristics. They can be grown chemically in a very easy and cheap way, assembled in the desired geometry by means of nano-lithography and directly connected to readout electronics devices. In addition, they can be coupled to silicon substrates to obtain mixed micro-nano structures with intermediate electronic properties. First radiation detectors prototypes have been realized using CNTs grown through a CVD (Chemical Vapour Deposition) process. These devices, sensitive to the radiation in the range from 335 to 850 nm, exibit a relevant increase in the photocurrent toward UV wavelengths both with continuous light and with pulsed radiation. The surface pixellization can be easily achieved using nano-lithography techniques at a very low cost. This approach lo- oks very promising also for the realization of nano-opto-electronic devices directly coupled with readout electronics as in the Medipix chip. In this talk, we propose a review of results obtained by the authors with detector prototypes made of multiwalled carbon nanotubes grown on sapphire and silicon substrates. Electrical and optical properties of detectors have been intensively studied as well as the coupling between nanotubes and silicon substrates. The strong matching between silicon and CNTs found suggests the possibility to realize a finely pixelled large area detector, UV sensitive, with submicron position accuracy. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Neutron detection through an SRAM-based test bench

    Page(s): 64 - 69
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1807 KB) |  | HTML iconHTML  

    In this paper, we propose a technique for the detection of neutrons that relies on the sensitivity of SRAM cells to particle radiation. In particular, we introduce a system based on a memory test bench that records the neutron reactions in the memory array. This system allows a good flexibility from different points of view. It is conceived to be modular, programmable, low power consuming and portable. Consequently, it can operate in various experimental conditions such as under artificial sources of particles as well as in natural ambience, from the Earth surface to spatial environment. The system is also independent of the type of memory, allowing the use and the study of the interaction between particles and electronic devices built with different technologies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Preliminary study on polycrystalline diamond films suitable for radiation detection

    Page(s): 70 - 75
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (391 KB) |  | HTML iconHTML  

    The microwave plasma enhanced chemical vapor deposition technique has been employed to grow polycrystalline diamond films on p-doped Si (100) substrates starting from highly diluted (1% CH4 in H2) gas mixtures. Coplanar interdigitated Cr/Au contacts have been thermally evaporated on two samples about 8 mum thick having different grain size. Dark current-voltage (I-V) measurements and impedance characterization have been found to be dependent on the grain size and on the quality of the examined samples. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On exploiting a latchup-based detector via commercial CMOS technologies

    Page(s): 76 - 78
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (715 KB) |  | HTML iconHTML  

    The stimulated ignition of latchup effects caused by external radiation has so far proven to be a hidden hazard. Here this effect is described as a novel approach to detect particles by means of a solid-state device susceptible to latchup effects. In addition, the device can also be used as a circuit for reading sensors devices, leaving the capability of sensing to external sensors. The paper first describes the state-of-the-art of the project and its development over the latest years, then the present and future studies are proposed. An elementary cell composed of two transistors connected in a thyristor structure is shown. The study begins using traditional bipolar transistors since the latchup effect is originated as a parasitic circuit composed of such devices. Then, an equivalent circuit built up of MOS transistors is exploited, resulting an even more promising and challenging configuration than that obtained via bipolar transistors. As the MOS transistors are widely used at present in microelectronics devices and sensors, a latchup-based cell is proposed as a novel structure for future applications in particle detection, amplification of signal sensors and radiation monitoring. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A self-triggered CMOS front-end for Silicon Photo-Multiplier detectors

    Page(s): 79 - 84
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (967 KB) |  | HTML iconHTML  

    A complete analog front-end channel suitable for Silicon Photo-Multiplier (SiPM) detectors has been designed in a standard CMOS 0.35 mum technology. The current-mode approach exploited in the first stage of the proposed architecture allows to fulfill the severe constraints imposed by this kind of detectors in terms of dynamic range and speed of operation, without excessive power consumption. Timing accuracy of about 50 ps, obtained with the electronics coupled to a fast pulse generator in series to a charge injection capacitance, has been obtained by means of a fast current discriminator. The circuit is specially intended for medical imaging applications, for instance PET, but programmability of detector bias, gain and threshold current enhances the flexibility of the architecture, making it suitable for different kind of SiPM detectors and applications. An 8-channel ASIC, suitable for the read-out of SiPM arrays has been designed and manufactured following this approach. The characterization of the chip is currently in progress. Here we report the preliminary measurement results obtained by coupling a single channel to a single SiPM detector excited by a pulsed blue LED. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Low-power sensor interfaces

    Page(s): 86
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (40 KB)  

    Sensor interfaces are a crucial and power-hungry part in many applications. Research is therefore needed to look for alternative solutions that reduce the power consumption of the interfaces while achieving the targeted accuracy and speed requirements. This invited talk reviews both existing and novel design solutions, based on both voltage-mode and time-mode signal processing. This is illustrated with some examples from automotive and other applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Smart CMOS temperature sensors

    Page(s): 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (44 KB)  

    Summery form only given. Smart sensors are systems in which sensors and dedicated interface electronics are integrated on the same chip, or at least in the same package. Due to the low-level analog output of typical sensors, designing interface electronics that ldquodoes no harmrdquo, i.e. does not impair sensor performance, is quite challenging, especially in today's mainstream CMOS technology, whose inherent precision is limited by 1/f noise and component mismatch. However, since most sensors are quite slow compared to transistors, dynamic techniques can often be used to trade speed or bandwidth for higher precision. Examples of such techniques are auto zeroing, chopping, dynamic element matching, switched-capacitor filtering and sigma-delta modulation. This paper describes the use of such dynamic techniques in the design and realization of state-of-the-art smart CMOS temperature sensors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An accurate RF 0°/180° phase splitter

    Page(s): 88 - 90
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1509 KB) |  | HTML iconHTML  

    In most receivers a balanced mixer is used, while the output of the LNA is single ended. The presented phase splitter generates an accurately balanced signal out of a single-ended source. The wide-band circuit consists of two RF transistors and a DC control loop. The circuit operates up to, say, fT/4. In the article the basic circuit is discussed and an IC implementation is given. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Behavioral modeling and simulation of a chemical sensor with its microelectronics front-end interface

    Page(s): 92 - 97
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (716 KB) |  | HTML iconHTML  

    A surface acoustic wave (SAW) device is used in this work as the sensing element for a chemical sensor that will be embedded in a wireless sensor node. The SAW device is intended to detect the concentration of gaseous mercury in the environment. Two behavioral models of the SAW device have been studied. The microelectronics front-end architecture has been designed at transistor level in a 0.35 mum CMOS technology. The SAW device is embedded in a phase-locked loop (PLL) that converts the change of concentration of gaseous mercury into a shift of the loop frequency. Finally, the simulation of the overall sensor has been carried out considering a model of the SAW device described in the Hardware Description Language Verilog-A. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A fast-developing and low-cost characterization and test environment for a double axis resonating micromirror

    Page(s): 98 - 103
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (459 KB) |  | HTML iconHTML  

    Testing and characterization of micro-electro-mechanical systems (MEMS) and micro-opto-electro-mechanical systems (MOEMS) can be very challenging due to the multi-domain nature of these devices. Nowadays high volume, high-cost, and accurate measuring systems are necessary to characterize and test MEMS and MOEMS especially to examine motions, deflections and resonance frequencies. This paper presents a fast-developing and low-cost environment for MEMS and MOEMS testing and characterization. The environment is based on a flexible mixed-signal platform, named ISIF (intelligent sensor interface). As a case study we consider the characterization of a double axis scanning micromirror. The testing environment has been validated by comparing measurement results with results obtained by finite element method simulation performed with Comsol Multiphysicstrade. Finally, these results have been used to create an electrical equivalent model of the micromirror. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.