UC Irvine

Infectious diseases have been notorious killers since the beginning of human history. As antibiotics were discovered to efficiently treat infectious diseases, they also cause antibiotic resistivity in bacteria. It could result in huge death tolls and economic losses if not being handled properly. As a potential tool to address these crises, centrifugal microfluidic platforms have been widely investigated for decades. In this work, we demonstrated the development of a centrifugal microfluidic platform for sample preparation of assays, including liquid manipulation via laser valves, cell lysis of gram-positive and gram-negative bacteria, and incubation of bacteria from different species. We also presented a novel recirculation mechanism for inward pumping, mixing, and hybridization enhancement. The mechanism was studied parametrically and theoretically to provide practical design guidelines. A recirculation integrated blood/plasma separation design was tested as a potential application. A preliminary study was carried out to show its potential in assay hybridization. Finally, we designed and fabricated a centrifugal disc, and used the platform we developed to implement a phenotypic antibiotic susceptibility test that successfully identifies antibiotic resistance against 5 types of antibiotics among 11 different species of E. Coli in 2 hours.