Surface-Machined Parylene Microfluidics
Jason Shih, Terry D. Lee and Yu-Chong Tai
from: Lab-on-a-Chip Technology (Vol. 1): Fabrication and Microfluidics (Edited by: Keith E. Herold and Avraham Rasooly). Caister Academic Press, U.K. (2009)
Over the last decade we have pioneered a unique technology for the realization of microfluidic components and systems. The technology is based around Parylene, a thin film, chemically inert, and biocompatible polymer deposited using a room temperature chemical vapor deposition (CVD) process. Surface micromachining, a common technique in microfabrication, is used to build up our fluidic structures one Parylene layer at a time. Using this technology, a portfolio of microfluidic components, ranging from pumps and valves, to flow and pressure sensors, have been demonstrated. Since all these components are produced using the same technology, the total integration of different components to form a system is feasible. The use of Parylene also ensures that the final microfluidic devices are biocompatible and chemically resistant to a broad range of solvents. Finally the use of microfabrication techniques allows us to batch fabricate devices simultaneously.Beyond the core Parylene surface micromachining technology, we have also developed additional methods to adapt our technology for different specific needs. These include the modification of the core technology to produce fluidic structures capable of sustaining pressures greater than 1000 psi for applications such as high performance liquid chromatography (HPLC). Also, we have demonstrated a modular concept where chips with different components can be connected together on a microfluidic breadboard.This chapter will begin by discussing Parylene, its material properties, and its applications to microfluidics. Detailed methods regarding the fabrication and implementation of microfluidic devices, components and systems will then follow. Several illustrative processes will provide the reader with the knowledge to replicate previously demonstrated devices as well as develop their own. Common pitfalls and solutions will also be discussed. Many examples of applications of this technology will be described, giving the reader a library of components which can be replicated and used. Finally, the advantages of this technology will be examined read more ...