Microfluidic systems that move and mix tiny amounts of liquids are used in laboratories for biotechnology, chemistry, and even the development of inkjet technology. Frequently, microfluidic devices are integrated into a single "lab on a chip" but fabricating such systems can be costly and time-consuming. Now, MIT researchers are using customized LEGO bricks to make a modular microfluidics platform. Their prototype system "could be used to manipulate biological fluids and perform tasks such as sorting cells, filtering fluids, and encapsulating molecules in individual droplets." From MIT:
To demonstrate modularity, (mechanical engineering grad student Crystal) Owens built a prototype onto a standard LEGO baseplate consisting of several bricks, each designed to perform a different operation as fluid is pumped through. In addition to making the fluid mixer and droplet generator, she also outfitted a LEGO brick with a light sensor, precisely positioning the sensor to measure light as fluid passed through a channel at the same location.
Owens says the hardest part of the project was figuring out how to connect the bricks together, without fluid leaking out. While LEGO bricks are designed to snap securely in place, there is nevertheless a small gap between bricks, measuring between 100 and 500 microns. To seal this gap, Owens fabricated a small O-ring around each inlet and outlet in a brick.
"The O-ring fits into a small circle milled into the brick surface. It's designed to stick out a certain amount, so when another brick is placed beside it, it compresses and creates a reliable fluid seal between the bricks. This works simply by placing one brick next to another," Owens says. "My goal was to make it straightforward to use."