UNIVERSITA’ DEGLI STUDI DI BRESCIA
Dipartimento di Ingegneria dell'Informazione - Elettronica, Informatica, Telecomunicazioni, Automatica
Research topics
1. ENERGY HARVESTING AND AUTONOMOUS SENSORS
M. Baù, S. Dalola, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Collaborations: Dip. Ingegneria Elettrica, Elettronica e dei Sistemi, Università di Catania - Dip. Fisica, Università di Perugia - MEGGIT-Ferroperm Piezoceramics, Kvistgaard (Denmark) - SENSOR Lab., Università di Brescia & CNR-IDASC.
2. PIEZOELECTRIC ACOUSTIC-WAVE SENSORS AND RELATED ELECTRONIC SYSTEMS
M. Baù, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Collaborations: Dep. Ingenieria Electronica, Universidad Politecnica de Valencia (Spain).
3. MEMS SENSORS AND INTERFACE CIRCUITS
M. Baù, S. Dalola, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Collaborations: Centro Nacional de Microelectronica (CNM), Barcelona (Spain) - Vienna University of Technology and Austrian Academy of Sciences, (Austria).
4. SENSOR SYSTEMS FOR FLUIDICS AND MICROFLUIDICS
M. Demori, V. Ferrari
Collaborations: Dept. Mechanical and Industrial Engineering, Università di Brescia - General Pathology and Immunology Unit, Università di Brescia.
5. SYNCHRONIZATION FOR INDUSTRIAL APPLICATIONS AND SMART GRIDS
C.M. De Dominicis, P. Ferrari, A. Flammini, S. Rinaldi, E. Sisinni, A. Vezzoli
Collaborations: University of Aachen, University of Cagliari, University of Firenze, University of Perugia, ABB Norway, Selta
6. INDUSTRIAL APPLICATIONS AND FIELDBUS
M. De Dominicis, P. Ferrari, A. Flammini, E. Sisinni
Collaborations: Hanyang University, Seoul, Korea, Bern University, EDF (Electricité De France) R&D, University of Sannio, Intellimech, Siemens
7. ELECTRONIC INTERFACES FOR MOX CHEMICAL SENSORS
A. Depari, A. Flammini, D. Marioli, E. Sisinni
Collaborations: University of L’Aquila, CNR, ENEA
8. MODELING OF ORGANIC AND INORGANIC THIN FILM TRANSISTORS
L. Colalongo, Z.M. Kovács-Vajna
Collaborations: Technische Universiteit (Eindhoven University of Technology), Department of Electrical Engineering - Eindhoven, The Netherlands
9. POWER HARVESTING FOR SELF-POWERED SENSORS
E. Sardini, M. Serpelloni
10. SENSOR SYSTEMS FOR HUMAN APPLICATIONS
V. Luciano, E. Sardini, M.Serpelloni
Collaborations: University of Catalunia, Universitè Pierre et Marie Curie Paris (UPMC).
11. TELEMETRIC MEASUREMENT SYSTEMS
E. Sardini, M. Serpelloni
Collaborations: University of Catania
12. THICK-FILM SENSORS FOR ACCELERATION AND TILT MEASUREMENTS
D. Crescini
ENERGY HARVESTING AND AUTONOMOUS SENSORS
M. Baù, S. Dalola, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Methods and devices to harvest energy from the environment are studied and exploited to supply power to autonomous sensor modules. The piezoelectric effect in lead-zirconate-titanate (PZT) films is employed to develop autonomous sensor modules powered by background vibrations. By combining energy harvesters, ultra-low-power circuitry, and adequate sensing strategies, battery-less vibration-powered sensors were developed which transmit measurement signals and/or identification codes over a radio-frequency link.
Within the project PRIN2009 (2011-2013): " Innovative solutions for enhanced energy harvesting from broadband and low-frequency vibrations in microsystems ", nonlinear phenomena and devices based on piezo-magnetic interactions have been proven to significantly improve the conversion effectiveness of broadband and random vibrations over the use of linear resonant converters.
The conversion of energy from temperature gradients exploiting the thermoelectric principle is also studied. Thermoelectric energy converters have been designed on silicon in MEMS BESoI technology.
Within the project IIT “NANOTHER the thermoelectric effect in innovative nanostructured materials is studied to develop next-generation thermoelectric generators (TEGs).
Pubblications 2011
1) M. Ferrari, M. Baù, M. Guizzetti, V. Ferrari, A single-magnet nonlinear piezoelectric converter for enhanced energy harvesting from random vibrations, Sensors and Actuators A, 172, 1, (2011) 287–292. ISBN/ISSN: 0924-4247.
2) M. Baù, M. Ferrari, V. Ferrari, Energy Harvesting from Vibrations by means of PZT Thick Films on Steel and Silicon Elastic Structures, Proceedings of Piezo 2011 Conference: Electroceramics for End-Users, Sestriere, Italy, 28 February-2 March, 2011, 9-13.
3) S. Dalola, V. Ferrari, Design and fabrication of a novel MEMS thermoelectric generator, Proceedings of the Eurosensors XXV Conference, Athens, Greece, 4-7 September, 2011, in Procedia Engineering, 25, (2011) 207-210. ISBN/ISSN: 1877-7058.
4) D. Alghisi, M. Ferrari, V. Ferrari, Active rectifier circuits with sequential charging of storage capacitors (SCSC) for energy harvesting in autonomous sensors, Proceedings of the Eurosensors XXV Conference, Athens, Greece, 4-7 September, 2011, in Procedia Engineering, 25, (2011) 211-214. ISBN/ISSN: 1877-7058.
5) S. Dalola, G. Faglia, E. Comini, M. Ferroni, C. Soldano, D. Zappa, V. Ferrari, G. Sberveglieri, Seebeck effect in ZnO nanowires for micropower generation, Proceedings of the Eurosensors XXV Conference, Athens, Greece, 4-7 September, 2011, in Procedia Engineering, 25, (2011) 1481-1484. ISBN/ISSN: 1877-7058.
PIEZOELECTRIC ACOUSTIC-WAVE SENSORS AND RELATED ELECTRONIC SYSTEMS
M. Baù, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Circuit configurations are studied to accurately detect the resonant response of quartz-crystal resonator (QCR) and other resonant sensors in order to extend their accuracy and operating range under heavy acoustic and dielectric loading.
Electronic techniques and circuits for interrogation of piezoelectric resonator sensors over a short-range electromagnetic link are investigated.
A developed technique is based on the separation in time of the excitation and detection phases, exploiting the sensing of the transient response of the resonator. An external primary coil is electromagnetically air coupled to a secondary coil connected to the electrodes of the resonator. During the excitation phase the fundamental thickness shear mode of the resonator is excited, while in the detection phase the excitation signal is turned off and the transient response of the resonator is contactless sensed by measuring the voltage induced back across the primary coil.
Experimental results have demonstrated the detection of relative humidity changes by a QCR sensitized with a hygroscopic coating. More generally the proposed technique can be exploited for the measurement of physical or chemical quantities affecting the resonant response of piezoelectric resonator sensors.
Pubblications 2011
1) M. Baù, M. Ferrari, E. Tonoli, V. Ferrari, Sensors and energy harvesters based on piezoelectric thick films, Proceedings of the Eurosensors XXV Conference, Athens, Greece, 4-7 September, 2011, in Procedia Engineering, 25, (2011) 737-744. ISBN/ISSN: 1877-7058.
2) M. Baù, M. Ferrari, V. Ferrari, E. Tonoli, Electromagnetic Contactless Interrogation Technique for Quartz Resonator Sensors, Proceedings of IEEE Sensors 2011 Conference, Limerick, Ireland, October 28-31, 2011, 1297-1300. E-ISBN: 978-1-4244-9288-6.
MEMS SENSORS AND INTERFACE CIRCUITS
M. Baù, S. Dalola, M. Ferrari, V. Ferrari, D. Marioli, E. Tonoli
Sensors fabricated in MEMS technology and other microfabrication technologies are studied together with tailored interface circuits.
A principle for contactless interrogation of passive micromechanical resonator sensors is proposed. The principle exploits an external primary coil electromagnetically air-coupled to a secondary coil which is connected to a conductive path on the resonator. The interrogation periodically switches between interleaved excitation and detection phases. During the excitation phase the resonator is driven into vibrations, while in the detection phase the excitation signal is turned off and the decaying oscillations are contactless sensed. The principle advantageously avoids magnetic properties required to the resonator, thereby ensuring compatibility with standard silicon microfabrication processes. The principle has been implemented on a MEMS SOI microcantilever resonator sensor with mechanical resonant frequency of 10.186 kHz and has been demonstrated to work over a distance of up to 1 cm.
Pubblications 2011
1) M. Baù, E. Tonoli, V. Ferrari, D. Marioli, Contactless electromagnetic switched interrogation of micromechanical cantilever resonators, Sensors and Actuators A, 172, 1, (2011) 195–203. ISBN/ISSN: 0924-4247.
SENSOR SYSTEMS FOR FLUIDICS AND MICROFLUIDICS
M. Demori, V. Ferrari
A sensor system for the study of oil-water flow in pipes has been developed. The estimation of the area fraction occupied by each fluid phase is done by capacitance measurements between electrodes flush-mounted on the external surface of a nonconductive section of the pipe. A sensor configuration has been developed that employs guard electrodes, coupled to a tailored electronic interface to drive the guard electrodes and amplify the measurement signal.
Microfluidic devices with embedded capacitive sensing have been developed. The devices are fabricated in a hybrid technology which innovatively combines PDMS (PolyDiMethylSiloxane) soft photolithography and screen printing techniques.
A microchannel, realized in a PDMS layer, is placed in the fringe field of a sensing capacitor formed by electrodes screen-printed on a glass substrate. Fluids inside the microchannel affect the capacitance that is measured by a tailored electronic interface system. Experimental results obtained for different fluids injected in the microchannel demonstrate the ability of the system to discriminate the fluids and estimate their dielectric permittivity both as pure samples and as mixtures at varying solute fractions.
Microfluidic sensors are being developed to detect flowing cells for cell sizing and counting.
Pubblications 2011
1) D. Strazza, B. Grassi, M. Demori, V. Ferrari, P. Poesio, Core-annular flow in horizontal and slightly inclined pipes: Existence, pressure drops, and hold-up, Chemical Engineering Science, 66, (2011) 2853–2863. ISBN/ISSN: 0009-2509.
2) D. Strazza, M. Demori, V. Ferrari, P. Poesio, Capacitance sensor for hold-up measurement in high-viscous-oil/conductive-water core-annular flows, Flow Measurement and Instrumentation, 22, (2011) 360–369. ISBN/ISSN: 0955-5986.
3) M. Demori, V. Ferrari, P. Poesio, D. Strazza, A microfluidic capacitance sensor for fluid discrimination and characterization, Sensors and Actuators A, 172, 1, (2011) 212–219. ISBN/ISSN: 0924-4247.
SYNCHRONIZATION FOR INDUSTRIAL APPLICATIONS AND SMART GRIDS
C.M. De Dominicis, P. Ferrari, A. Flammini, S. Rinaldi, E. Sisinni, A. Vezzoli
Synchronization is a hot topic in real-time distributed applications, with a special attention to Real-Time Ethernet and wireless fieldbus for industrial applications and to Smart Grids for energy distribution. IEEE1588 (PTP) and, particularly, the second version (2008), has gained the role of the reference standard in both application fields, but gateway should be designed to guarantee coexistence with existing solutions. Clock synchronization strictly depends on timestamping, but the research activity has deeply investigated about all the uncertainty sources. An intensive experimental work has been conducted in collaboration with Universities and private research centers, especially concerning synchronization for energy distribution and measurement. New studies have been conducted on synchronization capabilities in UWB-based systems and IPv6-based wireless sensor networks.
Pubblications 2011
1) M. Lixia, A. Benigni, A. Flammini, C. Muscas, F. Ponci, A. Monti, "A Software-only PTP Synchronization for Power System State Estimation with PMUs", 2011 IEEE Instrum&Meas Tech. Conf. (I2MTC), Hangzhou, China, May 10-12, 2011, pp. 855-860.
2) P. Ferrari, A. Flammini, S. Rinaldi, A. Bondavalli, F. Brancati, "Evaluation of Timestamping Uncertainty in a Software-based IEEE1588 Implementation", 2011, IEEE Instrum& Meas Tech. Conf. (I2MTC), Hangzhou, China, May 10-12, pp. 604-609.
3) P. Ferrari, A. Flammini, S. Rinaldi, G. Prytz, P. C. Juel, "Architecture of an embedded time gateway between PTP and SNTP ", 2011 IEEE Int. Symp. on Industrial Embedded Systems (SIES), Västerås, Sweden, June 15-17, 2011, pp. 71-74.
4) P. Ferrari, A. Flammini, S. Rinaldi, G. Prytz, "Applying PTP-to-SNTP Time-Gateway to IEC61850 systems", 2011 IEEE Conference on Emerging Technologies and Factory Automation (ETFA), Toulouse, France, September 5-9, 2011, pp. 1-4.
5) C. M. De Dominicis, P. Ferrari, A. Flammini, S. Rinaldi, M. Quarantelli, "On the Use of IEEE 1588 in Existing IEC 61850-Based SASs: Current Behavior and Future Challenges", IEEE Trans. Instrumentation and Measurement, September, 2011, Vol. 60, N. 9, pp. 3070-3081.
6) C. M. De Dominicis, A. Flammini, S. Rinaldi, E. Sisinni, A. Cazzorla, A. Moschitta, P. Carbone, "High-precision UWB-based timestamping", 2011 Int. IEEE Symposium on Precision Clock Synchronization for Measurement Control and Communication (ISPCS), Munich, Germany, September 12-16, 2011, pp. 50-55.
7) P. Ferrari, A. Flammini, S. Rinaldi, E. Sisinni, "Time distribution in IPv6 Wireless Sensor Networks", 2011 Int. IEEE Symposium on Precision Clock Synchronization for Measurement Control and Communication (ISPCS), Munich, Germany, September 12-16, 2011, pp. 69-74.
8) P. Ferrari, A. Flammini, S. Rinaldi, G. Prytz, "Time synchronization concerns in substation automation system", 2011 IEEE Int. Workshop on Applied Meas. for Power Systems (AMPS), Aachen, Germany, September 28-30, 2011, pp. 112-117.
9) A. Bondavalli, F. Brancati, A. Flammini, S. Rinaldi, "A Reliable and Self-Aware Clock for reference time failure detection in internal synchronization environment", 2011 IEEE Int. Workshop on Meas.& Networking (M&N), Anacapri, Italy, October 10-11, 2011, pp. 94-99.
10) A. Flammini, S. Rinaldi, A. Vezzoli, "The sense of time in Open Metering System", 2011 IEEE Int. Conference on Smart Measurements for Future Grids (SMFG), Bologna, Italy, November 14-16, 2011, pp. 22-27.
INDUSTRIAL APPLICATIONS AND FIELDBUS
C.M. De Dominicis, P. Ferrari, A. Flammini, E. Sisinni
Real-time industrial communications include Real-Time Ethernet applications and, recently, mesh wireless sensors networks as wirelessHART and ISA100.11a. Large plants are still under test and new algorithms and tools are to be developed, especially for the wireless networks. Software Defined Radio seems a promising architecture to solve the coexistence problem and to design a new generation of smart sensors using the cognitive approach; in addition, a sensor based on a SDR architecture can use the communication channel for ranging and measuring purposes.
Pubblications 2011
1) C. M. De Dominicis, A. Flammini, E. Sisinni, L. Fasanotti, F. Floreani, "On the development of a wireless self localizing streetlight monitoring system", 2011 IEEE Sensors Applications Symposium (SAS), San Antonio, TX, USA, February 22-24, 2011, pp. 233-238.
2) A. A. Memon, S. H. Hong, A. Flammini, "Load-Balancing Routing Algorithm for WirelessHART", 2011 Int. Conference on Communication and Electronics Information (ICCEI 2011), Haikou, China, February 22-24, 2011, pp. V1-14 - V1-18.
3) S. Baruffolo, M. Conforti, C. De Angelis, A. Flammini, E. Sisinni, "A finite element aided tool for the design of microwave resonant sensors", 2011 IEEE Instrumentation and Measurement Technology Conference (I2MTC), Hangzhou, China, May 10-12, 2011, pp. 1337-1341.
4) G. Donato, P. Ferrari, A. Flammini, "Helmet mounted data acquisition system for security and monitoring applications", 2011 IEEE Instrumentation and Measurement Technology Conference (I2MTC), Hangzhou, China, May 10-12, 2011, pp. 1633-1637.
5) P. Ferrari, A. Flammini, E. Sisinni, "New Architecture for a Wireless Smart Sensor Based on Software-Defined Radio", IEEE Trans. Instrumentation and Measurement, June, 2011, Vol. 60, N. 6, pp. 2133-2141.
6) C. M. De Dominicis, L. De Vito, P. Ferrari, A. Flammini, S. Rapuano, "Testing the transmission path of a Software Defined Radio Platform", 2011 International Workshop on ADC Modelling, Testing and Data Converter Analysis and Design (IMEKO IWADC 2011), Orvieto, Italy, June 30 - July 1, 2011.
7) P. Ferrari, A. Flammini, F. Venturini, A. Augelli, "Large PROFINET IO RT networks for factory automation: a case study", 2011 IEEE 16th Conference on Emerging Technologies and Factory Automation (ETFA), Toulouse, France, September 5-9, 2011, pp. 1-4.
8) Max Felser, Paolo Ferrari, Alessandra Flammini, “Chapter 39: Profinet”, The Industrial Electronics Handbook, Second Edition, Industrial Communication Systems, February, 2011, CRC Press
9) T. Dang, E. Sisinni, “Chapter 52: WirelessHART, ISA100.11a, and OCARI”, The Industrial Electronics Handbook, Second Edition, Industrial Communication Systems, February, 2011, CRC Press
ELECTRONIC INTERFACES FOR MOX CHEMICAL SENSORS
A. Depari, A. Flammini, D. Marioli, E. Sisinni
MOX chemical sensors appear as resistive sensors whose resistance can vary in a wide range, from tens of kOhms to more than tens of GOhms. Several new oscillating circuits have been proposed, together with a Least Mean Square approach, in order to evaluate sensor resistance. Most of the proposed circuits integrate current from sensor, that can be DC or AC powered. If capacitance need to be estimated, a transient is applied to sensor supply. The integrating circuit could lead to a long measuring time, especially with high-value resistance. New circuits have been proposed to shorten the measuring time, even with a wide range, taking advantage from moving thresholds or a mixed analog and digital approach. The new proposed circuits allow a constant measuring time, on the order of 10 ms, regardless the resistance value, still keeping the wide measuring range (more than five decades up to 100GOhm). Thanks to new developments, sensors can be managed by means of synchronized thermal profiles.
Pubblications 2011
1) A. Depari, A. Flammini, D. Marioli, E. Sisinni, E. Comini, A. Ponzoni, "An electronic system for the thermal management of MOX sensors", 2011 IEEE Sensors Applications Symposium (SAS), San Antonio, TX, USA, February 22-24, 2011, pp. 292-297.
2) A. Ponzoni, A. Depari, E. Comini, G. Faglia, A. Flammini, G. Sberveglieri, "Response dynamics of metal oxide gas sensors working with temperature profile protocols", Procedia Engineering - Eurosensors XXV, Athens, Greece, September 4-7, 2011, Vol. 1, pp. 1327-1330.
3) A. De Marcellis, G. Ferri, A. Depari, A. Flammini, "A novel time-controlled interface circuit for resistive sensors", 2011 IEEE Sensors, Limerick, Ireland, October 28-31, 2011, pp. 1137-1140.
4) A. Flammini, S. De Vito, "Chapter 3: Wireless Chemical Sensors", Chemical Sensors comprehensive sensor technologies Volume 6: chemical sensors applications, November, 2011, pp. 87-125.
5) A. Depari, A. De Marcellis, G. Ferri, A. Flammini, "A complementary metal oxide semiconductor-integrable conditioning circuit for resistive chemical sensor management", IOP Measurement Science and Technology, December, 2011, Vol. 22, N. 12, pp. 1-7.
MODELING OF ORGANIC AND INORGANIC THIN FILM TRANSISTORS
L. Colalongo, Z.M. Kovács-Vajna
Organic thin film transistors (OTFTs) as well as inorganic TFTs based on new materials (ex. Indium Gallium Zinc Oxide, IGZO) have gained considerable interest due to their potential applications in large-area, low-cost integrated circuits. Such applications include: driving devices for active matrix flat panel displays based on organic light emitting diodes, low-end smart cards, radio frequency identification tags, sensors, etc. Organic semiconductors for low-cost integrated circuits are typically deposited from solution leading to amorphous or polycrystalline thin films. Field-effect transistors based on such materials have several appealing features: the techniques for depositing films allow large areas to be coated, they can be vacuum-deposited at moderate temperatures, many polymers and oligomers are soluble and may be processed by spin coating. Furthermore, thanks to their intrinsic structural flexibility, in the case of all-polymer systems, OTFTs allow the production of flexible integrated circuits. The efficient design of complex integrated circuits based on TFTs and in particular OTFTs requires preliminary optimization and modelling. To this purpose, the availability of accurate analytical models (SPICE like) is very important. Our activity may be divided in three main areas: numerical simulation and physical modeling of OTFTs, analytical modeling (spice models), and development of TCAD tools for the design and verification of integrated circuits based on such materials.
Pubblications 2011
1) F. Torricelli, A. K. Tripathi, E. C. P. Smits, L. Colalongo, Zs. M. Kovacs-Vajna, G. H. Gelinck, E. Cantatore, Analysis and Modeling of Amorphous In-Ga-Zn-O (a-IGZO) Thin-Film Transistors, ICT.OPEN 2011 - Veldhoven, invited talk, Nov. 2011
2) F. Torricelli, L. Colalongo, L. Milani, Zs. M. Kovacs-Vajna, E. Cantatore, Impact of Energetic Disorder and Localization on the Conductivity and Mobility of Organic Semiconductors, Proc. of SISPAD 2011 - Osaka, pp. 195-198, Sep. 2011
3) F. Torricelli, E. C. P. Smits, J. R. Meijboom, A. K. Tripathi, G. H. Gelinck, L. Colalongo, Zs. M. Kovacs-Vajna, D. M. de Leeuw, E. Cantatore,Transport Physics and Device Modeling of Zinc Oxide Thin Film Transistors - Part II: Contact Resistance in Short Channel Devices, IEEE Transactions on Electron Devices, Vol. 58, No. 9, pp. 3025-3033, Sep. 2011
4) F. Torricelli, J. R. Meijboom, E. C. P. Smits, A. K. Tripathi, M. Ferroni, S. Federici, G. H. Gelinck, L. Colalongo, Zs. M. Kovacs-Vajna, D. M. de Leeuw, E. Cantatore, Transport Physics and Device Modeling of Zinc Oxide Thin Film Transistors - Part I: Long Channel Devices, IEEE Transactions on Electron Devices, Vol. 58, No. 8, pp. 2610-2619, Aug. 2011
5) D. Raiteri, F. Torricelli, E. Cantatore, A.H.M. van Roermund, A Tunable Transconductor for Analog Amplification and Filtering based on Double-gate Organic TFTs, Proc. of ESSCIRC 2011 - Helsinki (Finland), pp. 415-418, Sep. 2011
6) L. Milani, F. Torricelli, Zs. M. Kovacs-Vajna, L. Colalongo, Comparison Between Mobility Models in Organic Semiconductors, Proc. of International Conference on Organic Electronics (ICOE2011) ) - Rome, pp. 54-55, 2011
POWER HARVESTING FOR SELF-POWERED SENSORS
E. Sardini, M. Serpelloni
The research is focused on the study, design and development of power harvesters based on electromechanical transduction. Two devices are described here briefly.
Air temperature and velocity measurements are important parameters in many applications. A self-powered sensor placed in a duct and powered by an electromechanical generator scavenging energy from the airflow has been designed and tested. It transmits periodically the measured air temperature and velocity to a receiving unit. The system basically consists of two macro blocks, respectively, the self-power wireless sensor and the receiving unit. The self-powered sensor has a section devoted to the energy harvesting, exploiting the movement of an airscrew shaft keyed to a DC motor. The self-powered sensor adopts integrated devices in low-power technology, including a microcontroller, an integrated temperature sensor and a RF transmitter at 433 MHz. The data transmission is realized in Manchester encoding, with ASK modulation at 433 MHz, allowing to cover a distance between sensor and reader in the order of 4-5 meters depending on the power supplied in transmission. The air velocity is measured trough the rotor frequency of the electromechanical generator, while for the temperature a commercial low-power sensor is used. An experimental system has been designed and fabricated demonstrating that the airflow harvester can power the self-powered wireless sensor permitting air temperature and velocity measurements. The system can be used to real-time monitor of temperature and velocity. The sensor module placed in ducts does not require any batteries.
Mechanical energy in the form of low frequency vibrations (1–100 Hz) can be commonly available and this energy type can be advantageously converted to electrical one by exploiting energy harvesting techniques. At the same time, in many applications, the devices that convert low frequency mechanical energy to electrical one should have a small size. An electromechanical power generator is proposed for converting mechanical energy in the form of low-frequency vibrations, available in the measurement environment, into electrical energy. The intended applications for the proposed electromechanical power generator, described in this paper, are for examples mechanical systems with low frequency vibrations (1–100 Hz). The operating principle is based on the relative movement of a planar inductor with respect to permanent magnets. The generator uses polymeric material as resonators, which have low-frequency mechanical resonances due to the low Young's modulus of the materials by which they are made. The different materials, with which the suspensions for the planar inductor were made, have allowed to compare different behaviors of the resonators: linear and nonlinear. The proposed configuration can be adopted for its low profile, modularity and low-frequency vibrations in many applications from industrial to medical.
Pubblications 2011
1) E. Sardini, M. Serpelloni, “Self-powered wireless sensor for air temperature and velocity measurements with energy harvesting capability”, IEEE Transactions on Instrumentation and Measurement, 60(5), (2011), 1838–1844.
2) E. Sardini, M. Serpelloni, “An Efficient electromagnetic power harvesting device for low-frequency applications”, Sensors and Actuators A: Physical 172(2), (2011), 475-482.
SENSOR SYSTEMS FOR HUMAN APPLICATIONS
V. Luciano, E. Sardini, M.Serpelloni
The ability to monitor the health status of elderly patients or patients undergoing therapy at home enables significant advantages in terms of both cost and comfort of the subject. The research activity is concerned with the development of a novel wearable biomedical signal sensor device for monitoring health conditions at home. The wearable monitoring system consists of two subsystems: firstly, a wearable data acquisition hardware, where the sensors for acquiring the biomedical parameters are integrated, and secondly, a remote monitoring station placed separately and connected to internet for telemedicine applications. The physiological parameters that are monitored with the proposed instrumented wearable belt are electrocardiogram (ECG), heart rate (HR) derived from ECG signals by determining the R-R intervals, body temperature, respiratory rate, and three axis movement (acceleration and position) of the subject measured using an accelerometer. Human biomedical parameters can be registered and analyzed continuously during home work activities. Proper evaluation of those parameters would let immediately know about sudden health state changes, accidental injury or another menacing danger befalling patients at home.
Furthermore, in vivo monitoring of human knee implants after total arthroplasty increases information concerning articular motion and loading conditions. The autonomous sensor carries out force measurements in a protected environment and wirelessly transmits data directly from the inside of the implant to an external readout unit. The autonomous sensor is fully contained in the polyethylene insert of the prosthesis. Batteries are completely eliminated; the system gathers energy from an externally applied magnetic field using a miniature coil inside the implant. The forces transmitted across the knee joint during normal human activities such as walking, running or climbing can be directly measured. The device can be used to improve design, refine surgical instrumentation, guide post-operative physical therapy and detect human activities that can overload the implant. Furthermore, new devices for the generation of electricity applied to electronic instrumented total knee prosthesis have been developed. One work is a new proposed solution to monitor the forces into total knee prosthesis. This system consists in an electromagnetic generator in which the coil has been inserted in a prominent element of tibial prosthetic plate that is placed between the two condyle, while the magnets are placed into the condyles on the opposite surfaces. The electronic circuits and the force sensors are placed internally the tibial plate.
Pubblications 2011
1) Crescini D., Sardini E., Serpelloni M. Design and test of an autonomous sensor for force measurements in human knee implants. Sensors and Actuators A: Physical 166(1), (2011), 1-8.
2) Sardini E., Serpelloni M., Ometto M. Multi-parameters wireless shirt for physiological monitoring. MEMEA 2011, medical measurements and applications, Bari, Italy (2011), 316- 321.
3) Sardini E., Serpelloni M., Donzella G., Gazzoli M. Human knee prosthesis equipped with force sensors, BIODEVICES 2011, International conference on biomedical electronics and devices. January 26-29, Rome, Italy, (2011) 349- 352.
4) Sardini E., Serpelloni M., Luciano V., Baronio G. Analysis of electrical generator for power harvesting from human movements. BIODEVICES 2011, International conference on biomedical electronics and devices. January 26-29, Rome, Italy, (2011), 194- 198.
TELEMETRIC MEASUREMENT SYSTEMS
E. Sardini, M. Serpelloni
Telemetric measurement systems are an interesting solution to connect the probe positioned in the hazardous zone with the conditioning electronics in the safe zone. Moreover, they represent a viable solution when the measurement environment is contained in an enclosed and hermetic space and the required wire-link through the separating wall, between the harsh and safe zones, is not possible due to the presence of high pressure or to the use of expensive connecting techniques. The research regarded the possibility to measure telemetrically not only the capacitive sensors, but resistive sensors as well. Mathematical and simulation analysis were executed and a new method has been implemented. Furthermore, a telemetric system was proposed for the measurement of high temperatures in harsh industrial environments. A novel MEMS temperature sensor connected to a planar inductor, which is realized in thick film technology, constitutes the sensitive element. The common working principle of the MEMS sensor is based on the structural deformation that appears as consequence of a temperature increase. An equivalent circuit scheme of the variable capacitor and planar inductor has been analyzed.
Two telemetric measurement methods, relying on a frequency variation output, have been tested. The whole system has been tested in the laboratory and several results are reported. Finally, the sensor prototype was fabricated and successfully characterized up to 330°C, as a proof of concept of temperature sensing through passive wireless communication.
Pubblications 2011
1) Sardini E., Serpelloni M. High-temperature measurement system with wireless electronics for harsh environments. SAS 2011, Ieee sensors applications symposium. February 22-24, San Antonio, Texas, (2011), 256- 261.
2) Sardini E., Serpelloni M. Wireless measurement technique for telemetry low-value resistive sensors, Procedia Engineering, Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece, (2011) 1261-1264.
THICK-FILM SENSORS FOR ACCELERATION AND TILT MEASUREMENTS
D. Crescini
La ricerca si è posta come obiettivo principale quello di studiare l’applicabilità della tecnologia ibrida a film spesso multilayers nel campo del rilievo di grandezze fisiche quali accelerazioni ed inclinazioni a bassa dinamica per campi operativi in cui il low-cost è divenuto strategico. Le metodologie trasduttive scelte per la realizzazione dei sensori sono state principalmente tre: piezoresistiva, capacitiva e a trasferimento termico.
In particolare lo studio ha posto l’accento sulla definizione delle procedure di deposizione e trattamento termico dei films conduttivi e piezoresistivi. Sono stati infatti eseguiti diversi studi prendendo in considerazione inchiostri forniti da diverse aziende operanti nel settore della tecnologia ibrida a film spesso cercando di effettuare delle comparazioni prestazionali. Si sono eseguite inoltre diverse combinazioni variando sia il materiale costituente il substrato meccanico portante (acciai ferritici di diverse tipologie e ceramica) che la morfologia degli inchiostri con attivazione della fase funzionale a bassa o alta temperatura.
Unitamente agli argomenti prettamente riconducibili a questioni tecnologiche, sono stati seguiti e sviluppati anche gli aspetti legati allo sviluppo dell’elettronica. Si sono studiati i temi relativi alla struttura del primo front-end dedicato all’elaborazione dei segnali provenienti dalla sensore primario basandosi su approccio analogico. Si è quindi poi rivolto lo sguardo in direzione dei temi riguardanti le metodologie di compensazione delle derive termiche di zero e di sensibilità.
Infine si è strutturata e studiata la parte di elaborazione digitale con l’obiettivo di stabilire un canale di comunicazione dati compatibile con le richieste tipiche delle applicazioni auto motive o macchine movimento terra. Per questi ultimi settori si è scelta la comunicazione attraverso il bus di campo CanOPEN.
Pubblications 2011
1) D. Crescini “Thick-Film Tilt Sensors: Feasibility Study Example Using Free Convective Motion of An Heating Air Mass” Sensor+Test 2011 Conference Proceedings Nurnberg, Germany, pagg.1154-1160
2) D. Crescini and M. Romani ”Thick-Film Accelerometer/Clinometer” IEEE IM2TC 2011 Conference Binjiang, Hangzhou, China pagg.1745-1750