A Hybrid CMOS/PDMS Microsystem for Cell Culture and Incubation
Jennifer Blain Christen
May 24, 2007
Abstract
Since the 1950's, the microelectronics industry has seen a remarkable evolution from the centimeter-scale devices created by Jack Kilby to millimeter-scale integrated circuits fabricated by Robert Noyce to today's 8nm feature size MOS transistors. During this time, not only have exponential improvements been made in the size of the devices, but the CAD and workstation technologies have advanced at a similar pace enabling the design of truly complex systems on a chip. The microfabrication and micro-engineering advances that have made all this possible have depended upon the ability to produce integrated electronic components through rapid, low-cost techniques that yield highly accurate and reproducible structures. Adaptation of these silicon technologies for new materials, that is, the fabrication of silicone microfluidics through soft-lithography, are ushering us into a new era of technological advances in the life sciences and biotechnologies. Silicone, otherwise known as PDMS, microfluidic devices have demonstrated order of magnitude improvements in reaction efficiency and are changing the standards for life science research techniques. Yet, to truly advance micro-technology for the life sciences, we must move beyond lab-on-chip passive structures to devices that add active functions: autonomous closed-loop sensing, control and actuation. Such devices have the potential to change the state of the art not only in research settings but also medical diagnosis and disease treatment in point of care and field settings. In my doctoral dissertation research I have explored microsystems that do just that. Through the example of a hybrid microsystem for stand-alone cell culture and incubation, a micro-incubator, I have explored the architectural space for design of hybrid silicon-silicone systems and have investigated and will discuss the trade-offs in scaling, design, fabrication, and packaging. My work has an experimental, an analytical, as well as a computational component. I have also considered the usability and the environmental impact for such devices. My approach to microsystem integration demonstrates a new paradigm for the engineering of heterogeneous, structurally complex three dimensional biomedical micro-devices for the life sciences.
Biography
Jennifer Christen received a B.S. (1999), MS (2001) and Ph.D. (2006) in electrical and computer engineering from the Johns Hopkins University. Her dissertation focused on a hybrid PDMS microfluidics / CMOS micro-incubator for autonomous cell culture. Jennifer held a graduate research fellowship from the National Science Foundation and a G K-12 fellowship also from the National Science Foundation. She is currently a post-doctoral fellow at the Johns Hopkins School of Medicine in the Immunogentics department where she is working on a microfluidic platform for homogeneous (single strand) HLA (human leukocyte antigen) allele detection. Her broader research interests are in the design of analog and mixed-mode integrated circuits for direct interface to aqueous environments that incorporate biological materials and in bioelectronics.