The Lego robot
Sentosa et al., 2023, PLoS ONE
A robot made of Lego can quickly take an important step towards making machines made of DNA.
“This started as a graduate project in an undergraduate lab course,” says Rizal Hariadi at Arizona State University, who assigned his class to build tools using “frugal science”.
The robot a group of students built has proven to be extremely useful and resembles a single arm topped with a holder for cylindrical tubes. It performs a procedure to mix the liquid contents of the tubes, by first tilting the tubes from vertical to horizontal and then spinning them quickly. This creates a single liquid with a density that decreases uniformly from bottom to top.
The robot’s parts, including gears, connecting blocks, and two motors, all come from Lego kits. The only exception is the tube holder that the researchers had to 3D print. The robot’s design is a smaller and faster version of more traditional “gradient mixers”.
After being mixed by the Lego robot, the liquid can be used to purify tiny structures made of DNA molecules that researchers like Hariadi want to use as tiny machines. These machines can both perform tasks in cells and shed new light on how naturally occurring molecular machines, such as proteins, work.
Many conventional methods of creating density gradients require difficult to use and expensive machinery. The Lego robot created the necessary density gradient in just 1 minute, which accelerates increase overall purification.
Katherine Dunn at the University of Edinburgh in the UK says the robot could make the purification process both cheaper and faster.
The purge procedure involves devices other than the Lego robot, so the robot itself may not be useful to other labs that don’t already have this remaining equipment, Hariadi says. However, since it cost about $350 to make from Lego — about $100 cheaper than store-bought devices — it’s a convenient and accessible way to prototype devices that can improve existing lab routines, he says.
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