Title: Don Plumlee1, J' Steciak1, A'J' Moll2
1Ceramic MEMS Pollution Sensor
Don Plumlee1, J. Steciak1, A.J. Moll2 1University
of Idaho, 2Boise State University DPlumlee_at_boisest
ate.edu
Low Temperature Co-Fired Ceramics
Motivation
- Collaboration between Boise State University
(BSU) and Washington State University (WSU) - Sensor Probe inserted into soil for groundwater
vapor monitoring. - Analyzes vapor pollutant concentrations above
groundwater. - Data collected and broadcast from array of
sensors in real-time. - Objective Accurate Time/Space tracking of
chemical migration in groundwater vapor.
IMS Sensor
- Low Temperature Co-Fired Ceramics (LTCC)
- LTCC is a Glass/Alumina mixture that sinters at
Low Temperature (lt 900C) - The Ceramic substrate and embedded elements are
Co-Fired in one step. - Material in the green state is composed of
Glass, Ceramic and Organic binder - Raw LTCC is delivered as a flexible sheet called
Green Tape
Direct-Push Truck (Groundwater Application)
Sensor Probe Model (Groundwater Application)
LTCC-IMS Schematic
Design
Ion Mobility Spectrometer
LTCC-IMS Solid Model
Tyndall Gate Model
IMS Detection Capability
IMS Examples
High Electrode density in LTCC limits ion
diffusion and improves selectivity
- Advantages
- Detection Capability
- Distinguish different species
- Sensitive to ppm range
- Fast (20 samples/sec)
- Axial configuration
- Robust
- Partial list of Detectable Species
- Sensitive to both air and water born pollutants
- NH4, SO2, and NO2 are all Pollutants of
Interest in ID - Several HAP chemicals on list
- Ions are propelled through the electric field to
the collector grid - Larger ions move slower than smaller ions
- Ion Time of Flight can be correlated to
chemical species
- Modular design with 27 segments
- 156 Interconnected Layers
- 5 embedded metal gates
- 5 LTCC layers
- 2 metal ion gates
Fabrication
Co-Fire
Constrained Lamination
Trim Device Outer Surface
Assemble Segments
Cut-out Segments
Prepare Sheets
- Fire IMS in furnace
- Prepare Solder Pads
- Mill Sheet Patterns
- Print Circuits/Resistors
- Stack, Laminate
- Mount device in Tool
- Trim device on Lathe
- Insert device into cylinder
- Laminate to 1000 psi
- Route IMS Segments
- Clean Holes
- Align Segments on Pins
- Bond Segments
Acknowledgements
Future Work
Funded by the United States EPA under Contract
no. X97031101-0
- BSU students Greta Doyle, Seth Kuhlman, Brian
Jaques - BSU staff Molly Gribb, William Knowlton, Robert
Walters - DuPont Material Donations
- Agilent Equipment Donations
- Integrate IMS device and electronic controls into
housing at BSU - Test Integrated Sensor System in Real soil and
atmosphere situations