Hacked-together Lego Mindstorms bot kit brings science to a classroom near you

By Jessica Hall

Stanford researchers have hacked the Lego Mindstorms platform as a springboard to create a liquid-handling robotics kit, using inexpensive, off-the-shelf parts. They’re hoping to get the kits into classrooms and STEM-curious kids’ hands as soon as possible, to open up the “wet sciences” — biology, chemistry, and medicine — for people who don’t have access to a high-end lab.

“I saw how students and teachers were already using Lego robotics in and outside school, usually to build and program moving car-type robots, and I was excited by that — and the kids obviously as well,” said team lead Ingmar Riedel-Kruse. “But I saw a vacuum for bioengineers like me. I wanted to bring this kind of constructionist, hands-on learning with robots to the life sciences.”

To fill that vacuum, the team created their own desktop liquid-handling robots that approach the performance of the far more costly automation systems found at universities and biotech labs, Riedel-Kruse said.
It’s tough to get an heirloom-quality chemistry set, and even tougher to get lab-bench precision at the kitchen table. But the motorized Mindstorms can precisely pipette fluids into and out of cuvettes, microfuge tubes, and multiple-well plates — all of which see heavy rotation in laboratories. Depending on the design, the robot can handle liquid volumes smaller than a microliter, which amounts to a droplet “about the size of a single coarse grain of salt.” Riedel-Kruse believes that these robots might even be useful for specific professional or academic liquid-handling tasks where bespoke or commercial bots can cost thousands of dollars.
Rather than just expecting to dump money on single-shot kits, “We really want kids to learn by doing,” he says.
In their paper, the team puts forth step-by-step plans and several different experiments, targeted to grade-school students from elementary to high school ages. They also offer experiments that students can conduct using common household consumables like food coloring, yeast, or sugar. In one experiment, colored liquids with different solute concentrations are layered atop one another to teach about liquid density. Another test tests the pH of liquids, to see whether they are acids like vinegar or bases like baking soda. Still another experiment uses color-sensing light meters to line up color-coded test tubes.
Riedel-Kruse emphasized the interdisciplinary learning opportunities that the use of these kits would afford. “These robots can support a range of educational experiments and they provide a bridge between mechanical engineering, programming, life sciences and chemistry. They would be great as part of in-school and afterschool STEM programs,” he said. “We show that with a few relatively inexpensive parts, a little training and some imagination, students can create their own liquid-handling robot and then run experiments on it — so they learn about engineering, coding and the wet sciences at the same time.”
[Top image: Building a liquid-handling robot: Start with a Lego Mindstorms system (left); add a motorized pipette for dropping fluids (center), and perform simple experiments like showing how liquids of different salt densities can be layered. Credit: Riedel-Kruse Lab]