Advances in digital microfluidics have led to the promise of biochips for applications such as point-of-care medical diagnostics. These devices enable the precise control of nanoliter droplets of biochemical samples and reagents. Therefore, integrated circuit (IC) technology can be used to transport and process "biochemical payload" in the form of nanoliter/picoliter droplets. As a result, non-traditional biomedical applications and markets are opening up fundamentally new uses for ICs.
The goal of this project is to develop a design-automation infrastructure for reconfigurable microfluidic biochips. It envisions an automated design flow that will transform biochip research and their use, in the same way as design automation revolutionized IC design in the 80s and 90s. Design tools and optimization methods are being developed to ensure that biochips are as versatile as the macro-labs that they are intended to replace. The results from this research will enable a "panel" of concurrent immunoassay-based diagnostic tests on an integrated microfluidic processor biochip that can be "user-programmed", and which can provide results in real-time with picoliter sample/reagent volumes. Specific research tasks include control-path synthesis and microcontroller/microfluidics integration, chip optimization for multiplexed immunoassays, microfluidic logic gates for smart decision-making, and design for testability.
Miniaturized and low-cost biochips will revolutionize data analysis for air quality studies and clinical diagnostics, enabling a transformation in environmental monitoring, healthcare, exposure assessment, and emergency response. This project is especially aligned with the vision of functional diversification and "More than Moore", as articulated in the ITRS 2007, which highlights "Medical" as a "System Driver" for the future. The project bridges several research communities, e.g., microfluidics, electronic design automation, and biochemistry, and it provides interdisciplinary education to graduate and undergraduate students.
Microfluidics-based biochips enable the precise control of nanoliter volumes of biochemical samples and reagents. They combine electronics with biology, and they integrate various bioassay operations, such as sample preparation, analysis,separation, and detection. Compared to conventional laboratory procedures, which are cumbersome and expensive, miniaturized biochips offer the advantages of higher sensitivity, lower cost due to smaller sample and reagent volumes, system integration, and less likelihood of human error. As a result, advances in this area will revolutionize clinical diagnostics forhealthcare, DNA sequencing, drug discovery, and many other applications. This project was focused on developing design automation solutions for the droplet-based "digital" microfluidic technology platform and emerging applications. Advances in design and optimization will reduce cost, reduce time-to-response, and make these devices more practical for the commercial marketplace. A design-automation infrastructure for reconfigurable digital microfluidic biochips has been developed. The researc breakthroughs will enable "panel" of concurrent immunoassay-based diagnostic tests on an integrated microfluidic processor biochip that can be "user-programmed", and which can provide results in real-time with picoliter sample/reagent volumes. Specific advances included: 1) Biochip design based on control-flow and feedback: Control-path synthesis, integration of check-pointing mechanisms, and controller/microfluidics integration have been achieved; 2) Integrated synthesis and optimization: Scheduling, binding, module placement, droplet routing, pin assignment to electrodes for a pin-constrained biochip, and optimization for a multiplexed immunoassay have been demonstrated; 3) Digital microfluidic logic gates: These fluidic logic gates have been designed with potential application for smart decision-making and adaptive reconfiguration; 4) Design for testability: Testability considerations have been incorporated n the synthesis of biochips. The research fundings have been published as one book, four book chapters, over 20 journal papers, and over 30 conference papers. Two PhD students were trained and they successfully defended their PhD theses. Some of the technology developed in this project was licensed by Advanced Liquid Logic (ALL), a startup company from Duke University. ALL was acquired in 2013 by Illumina, a major sequencing company in San Diego, CA. It is therefore expected that the research advances from this project will soon be incorporated in product offerings soon.
