1. © Copyright 2002 ABB. All rights reserved. - Microelectromechanical Systems for Process Analytics IFPAC 2003 Dr. Berthold Andres ABB Automation Products Germany

2. © Copyright 2002 ABB Automation - 2 - Process Analyzer and Instrumentation  Water analysis  Gas analysis  Pressure transmitter  Flow transmitter

3. © Copyright 2002 ABB Automation - 3 - What are Microelectromechanical Systems (MEMS) Why use MEMS technology for process analytical ABB MEMS Projects Summary Agenda

4. © Copyright 2002 ABB Automation - 4 - Microelectromechanical System (MEMS) is a miniaturization technique based upon silicon wafer technology. This technology is a departure from the historical emphasis on the miniaturization of existing electrical, optical and mechanical assemblies What are Microelectromechanical System?  Examples

5. © Copyright 2002 ABB Automation - 5 - Why use MEMS in Process Analytical? Size effects: Cost of manufacturing Cost of Installation Analyzer Location Sampling systems Shelters 5 mm Small is beautiful !!

6. © Copyright 2002 ABB Automation - 6 - Manufactured in silicon wafer processes Highly reproducible Lower manufacturing cost for larger quantities Significantly smaller sizes Less consumables  longer time of operation Lower power demand Portability Installation at the source Faster response time possible Smaller dead volume Lower mass Shorter diffusion length Designed as integrated assemblies Further reduced size Reduced number of components Reduced integration time Faster cycle time Exchangeability of complete subassemblies Maintenance is simplified Why use MEMS in Process Analytical?

7. © Copyright 2002 ABB Automation - 7 - Where to use MEMS in Process Analytical? Two Types of MEMS Projects Analyzer Components Moderate Risk, High Reward Detectors, Valves, columns, ionization chambers,…. Complete MEMS Analyzers High Risk, High Reward GC, MS, Titration,….

8. © Copyright 2002 ABB Automation - 8 - 1994: Our first introduction of a MEMS sensor Designed as an integrated detector with Thin-film measuring resistor Thin-film reference resistor Membrane to control gas flow through detector Size ~ 2 sq mm Housing and electronics are added in the next step Conventional design MEMS design 100 mm10 mm Development of a Thermal Conductivity Detector (TCD) for gas analysis (e.g. Hydrogen in air, CO2 in air)

9. © Copyright 2002 ABB Automation - 9 - Thermal Conductivity Analyzer, Summary Development was a big success  Several thousands sold since introduction Drivers for success Size of TCD detector can be minimized without loosing sensitivity Better technical data because of smaller size Smaller thermal capacity of detector Faster response time We already knew the application from our standard detectors “Simple” design of the detector. Housing and pneumatical connections are added in another production process Market size is just large enough for the MEMS production Current drawback It is difficult to control the production process for small quantities over a longer period of time (thousand is still a small number for a MEMS process)

10. © Copyright 2002 ABB Automation - 10 - Realization of Micro GC with MEMS Components

11. © Copyright 2002 ABB Automation - 11 - Micro-Valve Technical Specifications Micro ball valve Electromechanically activated Ball size ~ 500 µm Plasma etching to get high precision valve seat Pressure range < 2 bar Power consumption < 300 mW

12. © Copyright 2002 ABB Automation - 12 - Micro Valve Array is required for Micro-GC Integration of multiple micro ball valves => Realization of dedicated flow schemes Summary Micro ball valves can be produced But: Production of micro ball valve arrays is very complex, overall yield is too low

13. © Copyright 2002 ABB Automation - 13 - Micro Flame Ionization Detector for Micro-GC Designed as an integrated detector silicon-glass technology integrated sample injection system integrated gold electrodes quartz capillary connectors MEMS design Conventional design 5 mm

14. © Copyright 2002 ABB Automation - 14 - Flame Ionization Detector, Summary Micro-FID has been built and is running Micro-FID shows typical problem of MEMS technology that not everything can be simply scaled down Quenching distance between flame and electrodes does not allow to reduce size of flame substantially  Current Micro FID has no substantial benefits compared to conventionally manufactured system

15. © Copyright 2002 ABB Automation - 15 - MEMS Thermal Conductivity Detector for Micro-GC Fast Response Time < 10 ms Low Detection Limit < 10 ppm Advantages: Small Thermal Capacity Small Dead Volume 1 mm

16. © Copyright 2002 ABB Automation - 16 - MEMS GC, Summary Single components can be successfully designed Complete GC Very complicate to go from prototypes to production Each component must be developed and trouble shot as an individual The integration of individual components is a second project and very complicated GC Market Volumes are not compatible with MEMS

17. © Copyright 2002 ABB Automation - 17 - Next step: Concept for Micro-Mass-Spectrometer Target: MMS with the size of a cellular phone Plasma Ion source Separator with 1mm length  No UHV required !

18. © Copyright 2002 ABB Automation - 18 - MEMS Mass-Spectrometer, Objectives Measuring principle or component must be scalable  ok for MS Concentrate on crucial parts of the system design where the MEMS technology can show all its advantages  e.g. mass separator Yield for MEMS processes, especially for difficult structures, is not always 100 %  MEMS should be split to several components which can be tested individually

19. © Copyright 2002 ABB Automation - 19 - MEMS Conclusions ABB has been successful at targeting analyzer components for the conversion to MEMS technology Success comes from the use of MEMS components in conventional or miniature systems Total integrated MEMS systems may require too much time to get out of the lab and become a real product