Microfluidic systems have the power to revolutionize medicine, energy, electronics and even space exploration. But the sheer size of the external equipment required for controlling these quarter-sized devices has limited their use in portable, wearable technologies.
Now Northwestern University researchers are pushing microfluidics closer to reaching its true potential.
In a recent study, the researchers discovered how to pre-program the devices’ network structures in a way that controls how fluids flow and mix throughout the micropipes. The result? A step toward smartly designed microfluidic systems that behave like a computer chip without relying on external components.
“Current microfluidic technology often requires a desktop full of equipment to operate something the size of a quarter,” said Northwestern’s Adilson Motter, senior author of the study. “We took the control that’s provided by external systems and built it into the device’s structure.”
The study was published today (Oct. 23) in the journal Nature. Motter is the Charles E. and Emma H. Morrison Professor of Physics at Northwestern’s Weinberg College of Arts and Sciences. Daniel Case, a graduate student in Motter’s lab, is the paper’s first author. The Northwestern team worked with collaborators at St. Louis University and the University of Normandy in France.
The team also increased the fluid’s flow rate by removing one of the hair-like channels in the system. Case likens this to Braess’s paradox, a famous mathematical observation that removing a road from a traffic network can improve traffic flow.
“In these networks, you have fluid streams from multiple pipes that are connected,” Case said. “Fluids collide with each other at the junction, and these collisions create inefficiencies, so connections in the network introduce localized regions of congestion. When you remove the channels that create these connections, you also remove points of collision.”