The research objectives and approaches of this project are focused on examining fluid flow at small scales. As the idea of scaling up microfluidics systems to millifluidic counterparts gains greater scientific attention, as opposed to the significant body of work scaling down to nanofluidics, this work focuses on a simple two-dimensional approach for micro- and milli-fluidics to create three-dimensional chemical profiles using single-layer microfluidic modules. Not only can a three-dimensional pattern be created, but with simple changes in the planar configuration, the three-dimensional chemical pattern can be controlled including through the speed of the fluid and the height of the channels. Future larger-scale fluidic experiments may have limitations due to resulting non-obvious three-dimensional profiles, which are dependent on basic parameter choices.
The society benefits are that findings from this project will be transformative and result in high-risk/high-payoff by expanding possibilities in areas such as embryonic development and optofluidics. This work will also have an impact in fields from small scale chemical mixing to developing future therapies through understanding disease related biological systems as well as to researchers in engineering, microfluidics, millifluidics, cellular stimulation, mixing layers, optical imaging, and chemical fabrication approaches. The education effort is to build an education and training pipeline for preparing future leaders in engineering and science. This will be accomplished through work with kindergarten to 12th grade students as well as graduate students. These efforts will include working with Pittsburgh's Lincoln Technology Academy, which is in one of the most academically challenged neighborhoods in Pennsylvania.
The research for this project came at an important time as manufacturing new products that have applicability to a range of applications that can be highly automated are important. Microfluidics is a market that has crossed the $1 billion mark and is projected to increase to over $3 billion within the next five years. While more traditional approaches in microfluidics have been making progress, the next generation will have to address scalability issues, which was one area where this project made significant progress. With this work as the sensitivity of chemical profiles to parameters has become more critical and as microfluidic applications have been scaled up to the millimeter range, these approaches benefited a diversity of areas including studies of model organism behaviors in microfluidics, optofluidics, and passive mixing. This work also may in the future provide insight into a diversity of other research areas and applications including engineering, microfluidics, millifluidics, topology optimization, cellular stimulation, mixing layers, optical imaging, and chemical fabrication approaches. One goal has been and continues to be to potentially commercialize some of these technologies in markets such as drug discovery and tissue engineering. Furthermore, by providing fundamental understanding, this research was targeted to ensure the successful implementation of these ideas in academia, government, and industry. This intellectual merit of this project investigated the idea of scaling up microfluidics systems to millifluidic counterparts as opposed to the many past advances regarding scaling down to nanofluidics. We worked on a simple 2D approach for micro- and milli-fluidics to create 3D chemical profiles including pattern inversions using single-layer microfluidic modules. Not only could a 3D pattern be created, but with simple changes in the 2D configuration, we controlled the 3D chemical pattern. We also investigated the causative parameters for these valuable and unanticipated 3D profiles. Future larger-scale fluidic experiments may have limitations due to these resultant, non-obvious 3D profiles, which are dependent on basic parameter choices. We developed experimental and theoretical microfluidic methodology to understand the changes in topology and pattern formation associated with scaling up from microfluidic to millifluidic systems. We then determined the response of the 3D pattern in the millifluidic systems with objects partially obstructing the main channel, which was critical when probing larger scale systems such as organized, 3D, multicellular systems. Our interdisciplinary, multifaceted approach required the combination of perspectives and skills from our team, which was uniquely qualified for this project by virtue of its diverse strengths in engineering, chemistry, biology, material science, and physics. We believe that our reported results are and will continue to be very useful to researchers in the fields of engineering, microfluidics, millifluidics, cellular stimulation, mixing layers, optical imaging, and chemical fabrication approaches. This broader impact interdisciplinary approach is generating great interest amongst researchers working in a wide variety of settings, including industry, universities, high schools, and national laboratories. The principal investigator envisions that this broad level of interest has led to the progressive development of interconnected training opportunities benefiting individuals from different educational levels and perspectives, including underrepresented and minority groups. We developed an outreach program with Pittsburgh’s Lincoln Technology Academy, which serves one of the most academically challenged neighborhoods in Pennsylvania and has a nearly 100% African-American student body. We also have successfully brought into our group underrepresented and minority members; this continues to diversify our group. The outreach activities have been furthered by our activities as the principal investigator has received a MARC Minority Faculty Mentor Award and is a member of the Sloan Foundation Ph.D. Minority Program. The principal investigator directed a research group which had members from minority and underrepresented groups in the scientific community. His goal was furthered in creating a pipeline of individuals by linking high school, undergraduate, and graduate student training. The results from our research over this 2 year grant have been presented in more than 10 peer-reviewed archival journal publications, and have provided support for 3 PhD students. The work has also been presented at a variety of conferences including the American Society of Mechanical Engineers International Mechanical Engineering Congress and Exposition and the Biomedical Engineering Society. Graduate students involved in this project developed a combined mechanics, chemistry, biology, and material science background that have made them highly valuable in industry and academics. In addition, the research of this project was fundamental, yet required an intuitive, hands-on understanding of engineering merged with computational approaches and chemistry. This combination of skills provided them a unique training for a graduate-level project. Students in this program also benefited greatly from interactions with engineering and biology faculty. The graduation of these students helped address the growing industry and scientific need for multidisciplinary engineers, who are comfortable working in teams of diverse technical background.
