Elementary and secondary school students who later want to become scientists and engineers often get hands-on inspiration by using off-the-shelf kits to build and program robots. But so far it’s been difficult to create robotic projects to foster interest in the “wet” sciences – biology, chemistry and medicine – so called because experiments in these field often involve fluids.

Now, Stanford bioengineers have shown how an off-the shelf kit can be modified to create robotic systems capable of transferring precise amounts of fluids between flasks, test tubes and experimental dishes.

By combining the Lego Mindstorms robotics kit with a cheap and easy-to-find plastic syringe, the researchers created a set of liquid-handling robots that approach the performance of the far more costly automation systems found at universities and biotech labs.

“We really want kids to learn by doing,” said Ingmar Riedel-Kruse, assistant professor of bioengineering, 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,” said Riedel-Kruse, who is also a member of Stanford Bio-X.

In their PLoS Biology 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 consumables 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 said. 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.

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

Details on construction and programming of the robot can be found onthe PLOS website by clicking on this link.