Lego robot squirts liquids in DIY lab for kids

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A new set of liquid-handling robots—made from the Lego Mindstorms robotics kit and a cheap, easy-to-find syringe—can transfer precise amounts of fluids among flasks, test tubes, and experimental dishes.

The robot approaches the performance of automation systems found at university at biotech labs.

“We really want kids to learn by doing,” says Ingmar Riedel-Kruse, assistant professor of bioengineering at Stanford University, who led the team that reports its work in the journal PLOS Biology.

“We show that with a few relatively inexpensive parts, a little training, and some imagination, students can create their own liquid-handling robots and then run experiments on it—so they learn about engineering, coding and the wet sciences at the same time,” says Riedel-Kruse, who is also a member of Stanford Bio-X.


The ‘wet sciences’

These robots are designed to pipette fluids from and into cuvettes and multiple-well plates—types of plastic containers commonly used in laboratories. Depending on the specific design, the robot can handle liquid volumes far smaller than one microliter, a droplet about the size of a single coarse grain of salt. Riedel-Kruse believes that these Lego designs might even be useful for specific professional or academic liquid-handling tasks where related robots cost many thousands of dollars.

His overarching idea is to enable students to learn the basics of robotics and the wet sciences (biology, chemistry, medicine) in an integrated way. Students learn STEM skills like mechanical engineering, computer programming, and collaboration while gaining a deeper appreciation of the value of robots in life sciences experiments.

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Riedel-Kruse says he drew inspiration from the so-called constructionist learning theories, which advocate project-based discovery learning where students make tangible objects, connect different ideas, and areas of knowledge and thereby construct mental models to understand the world around them. One of the leading theorists in the field was Seymour Papert, whose 1980 book Mindstorms was the inspiration for the Lego Mindstorms sets.

“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,” he says. “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.”

‘It’s kind of easy’

In their paper, the team offers step-by-step building plans and several fundamental experiments targeted to elementary, middle, and high school students. They also offer experiments that students can conduct using common household products like food coloring, yeast, or sugar. In one experiment, colored liquids with distinct salt concentrations are layered atop one another to teach about liquid density. Other tests measure whether liquids are acids like vinegar or bases like baking soda, or which sugar concentration is best for yeast. Yet another experiment uses color-sensing light meters to align color-coded cuvettes.

The coding aspect of the robot is elementary, Riedel-Kruse says. A simple programming language allows students to place symbols telling the robot what to do: Start. Turn motor on. Do a loop. And so forth. The robots can be programmed and operated in different ways. In some experiments, students push buttons to actuate individual motors. In other experiments, students preprogram all motor actions to watch their experiments executed automatically.

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“It’s kind of easy. Just define a few parameters and the system works,” he says, adding, “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.”

Open-source instructions

Riedel-Kruse says these activities meet several important goals for promoting multidisciplinary STEM learning as outlined by the Next Generation Science Standards (NGSS) and other national initiatives. He stresses the cross-disciplinary instruction value that integrates robotics, biology, chemistry, programming, and hands-on learning in a single project.

The team has co-developed these activities with summer high school students and a science teacher, and then tested them with elementary and middle school students over the course of several weeks of instruction. These robots are now ready for wider dissemination to an open-access community that can expand upon the plans, capabilities, and experiments for this new breed of fluid-handling robots, and they might even be suitable to support certain research applications.

“We would love it if more students, do-it-yourself learners, STEM teachers, and researchers would embrace this type of work, get excited, and then develop additional open-source instructions and lesson plans for others to use,” Riedel-Kruse says.

See the PLOS Biology paper and Riedel-Kruse’s lab website for materials and instructions.

Source: Stanford University