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Self-Organization of Fluids in a Multienzymatic Pump System
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posted on 2019-02-05, 00:00 authored by Subhabrata Maiti, Oleg E. Shklyaev, Anna C. Balazs, Ayusman SenThe
nascent field of microscale flow chemistry focuses on harnessing
flowing fluids to optimize chemical reactions in microchambers and
establish new routes for chemical synthesis. With enzymes and other
catalysts anchored to the surface of microchambers, the catalytic
reactions can act as pumps and propel the fluids through the containers.
Hence, the flows not only affect the catalytic reactions, but these
reactions also affect the flows. Understanding this dynamic interplay
is vital to enhancing the accuracy and utility of flow technology.
Through experiments and simulation, we design a system of three different
enzymes, immobilized in separate gels, on the surface of a microchamber;
with the appropriate reactants in the solution, each enzyme-filled
gel acts as a pump. The system also exploits a reaction cascade that
controls the temporal interactions between two pumps. With three pumps
in a triangular arrangement, the spatio-temporal interactions among
the chemical reactions become highly coordinated and produce well-defined
fluid streams, which transport chemicals and form a fluidic “circuit”.
The circuit layout and flow direction of each constituent stream can
be controlled through the number and placement of the gels and the
types of catalysts localized in the gels. These studies provide a
new route for forming self-organizing and bifurcating fluids that
can yield fundamental insight into nonequilibrium, dynamical systems.
Because the flows and fluidic circuits are generated by internal chemical
reactions, the fluids can autonomously transport cargo to specific
locations in the device. Hence, the findings also provide guidelines
to facilitate further automation of microfluidic devices.