Figure 1. Top view of plastic sensor laminates
P.M. Martin and D.W. Matson
This project is developing the capability to fabricate microscale components and systems in ceramics, high temperature materials, and plastics. Microscale components used in many chemical and energy systems must be able to withstand high temperature and chemically harsh environments. Nonreactive plastic microscale components are needed for fluid flow, dialysis, pathogen detection, and medical applications
The primary objective of this project is to develop novel processes for the fabrication of microscale components from plastic and ceramic materials. Development of generic fabrication capabilities using these nontraditional (for microscale systems) materials has been deemed critical for various projects on Micro Chemical and Thermal Systems. Methods are being developed to fabricate microscale components from ceramic and ceramic/metal composite materials for high temperature chemical processors, and from plastic materials for microscale and mesoscale fluid flow, chemical, pathogen detection, and medical systems. The project also investigates techniques to integrate these components into micro and mesoscale systems. During its three year duration this project will establish the following capabilities:
Ceramic and metal coatings will be used to increase the functionality of the plastic and ceramic microcomponents. For example, hydrophobic and hydrophilic coatings can be applied to membranes and flow channels. Metal and semiconductors can be applied to form heaters, circuitry, and sensors.
In this project, which was started in FY 98, we have shown considerable success in the development of plastic laminated multilevel microfluidic devices suitable for low temperature analytical applications. Stacking technologies refined under this project were instrumental in producing a laminated groundwater chromium sensor as well as microdialysis devices used to prepare microsamples for mass spectrometric analysis. A top view of the laminated sensor is shown in Figure 1. The functions of the laminates used in the sensor were reservoirs, mixing, reaction, and detection functions. Typical channel widths were 100 These are the first known devices that incorporate micropumps with multiple levels of functional laminates.
Figure 1. Top view of plastic sensor laminates
In the area of ceramic bonding, we demonstrated the capability to bond and fire ceramic tape into solid We also have developed processes for cutting microstructures into commercially available green ceramic tape so that, when bonded, microchannels can be produced in the body of the solid ceramic device.
A sample with bi-directional thermal conductivity was fabricated using copper and stainless steel laminates. Modeling showed a 100:1 decrease in the effective thermal conductivity across the laminates compared to the direction along the laminates. Figure 2 shows a cross section of a Cu-Stainless Steel laminate. Work is currently ongoing to determine the thermal conductivity of the laminated specimens. Copper-clad ceramic laminates have been obtained to produce laminated ceramic/metal specimens. This material should have a 1000:1 inhomogeniety in thermal conductivity.
Figure 2. Cross section of copper-stainless steel laminate
"Fabrication of Plastic Microfluidic Components", P. M. Martin, D. W. Matson, W. D. Bennett, D. J. Hammerstrom, SPIE Proceedings 3515, 1998.
"Fabrication Processes for Polymer-Based Microfluidic Analytical Devices", D. W. Matson, P. M. Martin, W. D. Bennett, D. E. Kurath, Y. Lin, and D. J. Hammerstrom, Proceedings of µ-TAS '98, 1998.
Section of book: Microreactors-New Technology for Modern Chemistry, V. Vessel, ed.
"Laminated Plastic Microfluidic Components for Biological and Chemical Systems", P. M. Martin, D. W. Matson, W. D. Bennett, to appear in Journal of Vacuum Science and Technology
"Laser Machined Components for Microanalytical and Chemical Separation Devices" D. W. Matson, P. M. Martin, W. D. Bennett, proceedings of the SPIE International Symposium on Intelligent Systems and Advanced Manufacturing
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