srd419 by mudoc123

VIEWS: 32 PAGES: 30

									        Delivering the Promise of Surface Acoustic Wave Sensors




January 2010                                                  Page 1
                                    What’s a wireless and passive sensor?


•    « Standard » wireless sensor




•    SAW wireless AND passive
     sensor




January 2010                                                          Page 2
                           Value added by SENSeOR’s solutions


• Wireless – up to several meters

• Passive – no battery required, no electronic at the sensor level

• Robust, reliable, stable – well adapted for harsh environments

• Miniature – small, light, multifunction devices

• High performances and reliability – unique sensitivities and
  ranges

• Cost effective and green technology (no recycling of battery)


January 2010                                                  Page 3
               How it works!




January 2010                   Page 4
                                           SAW Technology - Introduction

• Based on their piezoelectric properties, certain materials such as Quartz
  (SiO2), Lithium Niobate (LiNbO3) and Lithium Tantalite (LiTaO3) create a
  mechanical displacement (surface acoustic waves - SAW) if an electric field
  is applied.

• The propagation of the SAW depends on the geometry of the substrate
  and the material parameters. These material constants are subject to
  environmental conditions:
       – mass loading (electrode, silica, additional layer ..)
       – stress (external forces, differential thermal stress)
       – Temperature

• Sensing with acoustic waves is based on measuring variations of acoustic
  propagation velocity of wave, or wave attenuation.

• 2 types of structures : resonators and delay lines


January 2010                                                               Page 5
                                        Principle of SAW sensors (resonators)

                                        (e.g. 434MHz)




                      


          Interrogation signal to the sensor (f0)          
          Generation of an acoustic wave on the piezoelectric
         substrate                                                Piezoelectric substrate
          Response of the sensor sent back to the interrogator
                                                                                        Mechanical
         (f0+DF according to temperature for example)                                   displacement


January 2010                                                                                  Page 6
                                       Principle of SAW interrogation




1. RF Pulse sent            2. Load of the            3. Answer from                  4. Answer
      to the                 resonators               the resonators                   analysis
   resonators


                                                       discharge




                              charge
Interrogator                                                           Interrogator

                   Sensor                    Sensor                                      P, T, ID, etc.




 January 2010                                                                                 Page 7
                                                         SAW Resonators

•      A resonator is composed of IDTs in the center of the
       structure and reflecting gratings or electrodes on
       both sides of the IDTs.

•      The IDT is a bi-directional structure, it means the
       energy propagates on both sides at the same
       intensity. The reflecting gratings or electrodes
       reflect the energy produces by the IDT.                   Resonator Principle

•      A resonant cavity is obtained and characterised by
       its resonant frequency.

•      Advantages: high quality factor, low insertion losses

•      Disadvantages:     frequency        sensitivity     to
       manufacturing tolerances

                                                                 Example of realization
                                                                      (8x4mm)
    January 2010                                                                    Page 8
                                         Example of a SAW pressure sensor

This SAW sensor is composed of 3 SAW
resonators located on the same substrate (Qz):
• Resonator n°3 (resonant frequency f3) is
located on the diaphragm done by quartz
micromachining and will be sensitive to
pressure and temperature
• Resonators n°1 (resonant frequency f1) and
n°2 (resonant frequency f2) will not be sensitive
to pressure but only to temperature
• Therefore :
 D(f3-f2)  information about pressure
variations
 D(f1-f2)  information about temperature
variations

•Other types of structures can be used
according to the pressure measurement range,
in particular for high pressure


  January 2010                                                          Page 9
                                Frequency response of a SAW pressure sensor




   F1 (red)
   F2 (green)
   F3 (blue)




      Example of frequency response of a SAW pressure sensor at 434MHz
                        (frequency variations from 0 to 5bars)




January 2010                                                             Page 10
                                             SAW Delay Lines

• A delay line is composed of IDTs at one side of
  the device and reflecting gratings or electrodes
  at the other side. The IDT generates an
  impulse wave which propagates to the
  electrodes. The impulse wave is reflected by
  the electrodes or reflecting gratings to the IDT.
                                                      Principe de la ligne à retard
• We therefore measure the propagating time of
  an impulse.
• Advantages: no sensitivity of phase shifts    to
    manufacturing tolerances

• Disadvantages: larger size than resonators for
  the same Q factor, higher insertion losses
                                                        Exemple de réalisation
                                                             (9x3,8mm)

 January 2010                                                                Page 11
               The products and applications




January 2010                                   Page 12
                                             Our offer to your applications

   Technology & Core Benefits               Unique sensing              Applications
                                              solutions
                                                               Rotating and moving parts
                                             Temperature       Inside engines, turbines, pumps,
                                                                      tyres, gearboxes…

                                                                   Harsh environments
                                                                 High temperatures (ovens…),
                                                               strong electromagnetic fields (HV
                            Wireless
                                            Stress, Pressure      breaker boxes…), explosive
                                                                        atmospheres…
                           Batteryless

                         Works where no                              Confined places
                          others work                             Inside materials (concrete,
                        High performance,                       plastic,…), underground pipes,
                          cost effective    Others to come         tanks, industrial valves…
                        Compact , Robust     (e.g. chemical)
               Green technology

January 2010                                                                            Page 13
                                                Main products available

• Wireless SAW Temperature sensors
       – typical measurement range from -40°C up to +200°C – ongoing projects for high temperatue
         up to +400°C
       – SED100 in thermowell packaging
       – One product in production (4000pcs/year) for marine application in diesel engines

• SAW starter kit
       – SAW TDK1 with SAW temperature sensors – used for feasibility study in customers
         environment

• SAW pressure and SAW stress sensors
       – Prototype available for pressure measurement range up to 20bars
       – SAW stress resonator available for tests

• Wireless SAW readers
       – Working at 434MHz
       – EC certified


January 2010                                                                               Page 14
                             Optimisation of each element of the system


• Based on customers specifications, Senseor has competencies
  to optimise the whole system

       – The wireless SAW reader (EC certified)



       – The SAW sensor
                                                            Examples of SAW sensors
                                                    Left : SAW temperature sensor 5x5mm
                                                   Middle : SAW stress resonator 7x5.2mm
                                           Right : SAW temperature sensor (delay line) 9x3.8mm


       – The antennas                                            Meander antenna at 434MHz
                               3 cm


                                       11 cm


January 2010                                                                            Page 15
                          Temperature measurement in marine diesel engines



• SAW temperature sensor (delay
  line) placed on the rotating part
• Interrogation through a fixed
  antenna
• Direct        and       continuous
  measurement of temperature
• Compact and simple installation




                                                      Source : Kongsberg Maritime


January 2010                                                                   Page 16
                                       Configuration with fixed interrogator linked to a PC




Possible interfaces:
  Wireless (Zigbee,
  Bluetooth…)
  Analog (0-5Volt)
  RS232 / USB
  CANBus…



                                                                       SAW sensor
                    Fixed reader connected through
                               RS232 to a PC
                  (IHM software supplied to monitor
                        real-time measurements)



   January 2010                                                                     Page 17
                        Multi-sensors configuration – example inside a
                                       confined space



• Senseor has developed a SAW reader able to interrogate up to
  12 sensors with one single antenna (each sensor having its
  own resonant frequencies)




January 2010                                                      Page 18
                        Multi-sensors configuration with multiplexing of
                                           antennas



• Senseor has developed a SAW reader with up to 4 antenna
  outputs in order to allow the interrogation of multiple sensors
  in different places with one single reader




January 2010                                                       Page 19
                             SAW sensors on rotating parts


• Being wireless and very light (2g only), the SAW sensor can be
  easily placed on rotating parts (such as rotors, tires…)




January 2010                                                 Page 20
                                                   SAW Temperature Evaluation kit –
                                                            SAW TDK1




    SAW sensor in
thermowell packaging
     with antenna
      (SED100)




        SAW sensor probe
         (6mm diameter)      SAW sensor with PIFA antenna for    SAW reader V3.3 with monopole antenna and
     with antenna – SED120   temperature monitoring of surface   USB connection

 January 2010                                                                                       Page 21
                                      Formerly unachievable sensing
                                        solutions…on moving parts


• Wireless bearing temperature monitoring
       – System certified for diesel engines in marine environment (based on
         delay lines) : temperature up to 170°C, sensor passage speed up to
         80m/sec, typ. accuracy +/-1°C

• Motors and tires temperature monitoring
       – Temperature up to 200°C
       – Up to 5000rpm

• Key benefits
       – significantly reduced risk of unforeseeable repair costs, improved
         operational safety, reduced false alarm rate, compact and simple
         installation, improved machines performances


January 2010                                                                  Page 22
                                    Formerly unachievable sensing solutions…in
                                                 confined spaces


•    HV equipments
       – Multiple sensors interrogation (e.g. 10), optimization of the sensor by selecting the
         frequency (between 433MHz and 2.45GHz) and the piezoelectric substrate

•    Level measurements inside tanks
       – Sensor immerged inside hydrocarbons, interrogation through polyethylene walls of
         tanks, detection of level variations of few cm

•    In-concrete building and soil
       – range of 30 cm demonstrated in wet soil (first trials), complement to current Ground
         Penetrating Radar (GPR) methods (“cooperative target”)

•    Implantable blood pressure
       – Miniature implantable pressure and temperature sensor at 2.45GHz

•    Key benefits
       – No battery and wireless: compatible with long-term monitoring of building,
         biocompatible, high reliability of sensors inside tanks (no problems with cables and
         electronics)


January 2010                                                                                     Page 23
                              Formerly unachievable sensing solutions…in
                                         harsh environments


• In high electrical and magnetic fields
       – SAW sensors are able to withstand to 2T magnetic field, 10kV voltage
         and 2kA current (tests already performed under these conditions)


• In high temperature
       – Some piezoelectric materials are well suited to temperature
         measurements up to 400°C (even 600°C): research programs are in
         progress to address this subject


• Key benefits
       – Robust and reliable solutions for the monitoring of critical parts in a
         process or in a machine


January 2010                                                                   Page 24
               The Company




January 2010                 Page 25
                                      Overview of the company

• SENSeOR has been created in February 2006 by Gerhard HEIDER to
  combine world-leading competencies and capabilities in acoustic wave
  (e.g. SAW) based sensing.

• SENSeOR’s headquarter is located in Sophia-Antipolis science park (French
  Riviera), and an additional office is located in Besançon, allowing a close
  collaboration with the French public research institute.

• SENSeOR comprises 19 employees, with a majority of PhD.

• Total income mainly in France. Expanding sales to Germany, Italy, USA /
  Canada

• Our business model:
   – Sales of custom-designed systems
   – Sales of standard products: SAW temperature sensors, SAW readers…

January 2010                                                             Page 26
                                           SENSeOR’s expertises


• SENSeOR’s expertises cover every phase of your project:
       – Study and consultancy: evaluation of fit with your requirements, use
         of unique simulation tools for fastest time-to-market, starter kits for
         immediate tests in your configuration

       – Development and integration: from components to complete
         systems, with assistance for validation and integration in your
         application, protected by patents

       – Custom solutions for production: from low to high volumes
         production capabilities through ISO TS certified partners, insurance of
         multiple sourcing



January 2010                                                                Page 27
                                   Leading capabilities


• Unique simulations tools

• Extensive portfolio of technology bricks and IP

• Strong partnerships with leading research institutes and
  founders

• Effective development kits

• Strong technical support




January 2010                                                 Page 28
                                                 Conclusion

  • SAW sensors offer a technological breakthrough:
          – Small, passive, wireless
          – Compatible with use in severe environments and/or on moving objects
          – Reliable, cost effective


  • SAW sensors are already used in commercial applications:
          – SAW temperature sensors for diesel engines
          – SAW stress sensors
          – SAW chemical and biological sensors


  • Senseor has the objective of being your industrial partner to
    deliver the promise of SAW sensors


January 2010                                                             Page 29
               www.senseor.com




January 2010                     Page 30

								
To top