More than a half century after it hit shelves, the humble Lego brick remains a wildly successful toy, thanks to the building block’s versatility as well as multiple licensing deals over the last decade (which, most recently, catapulted the company over Mattel to make it the top toy maker in the world).
But Lego bricks have also occasionally found their way into laboratories as tools for scientific research. A team at The University of Cambridge, for instance, used the bricks to build synthetic bones.
Now, researchers at Iowa State University have turned to transparent Lego bricks as a novel, low-cost way to study plant growth. The work, recently published in the journal PLOS One, argues that the bricks can be used to create highly precise, centimeter-scale systems with chemical gradients to study how chemical changes affect root growth.
Understanding how chemical and environmental changes affect plant root growth could increase crop yields and give us a better understanding of how certain crops will react to climate change.
Ludovico Cademartiri, an assistant professor of materials science and engineering at Iowa State University and a co-author of the paper, told Smithsonian.com that the idea of using Legos came out of a brainstorming session sparked by how surprisingly little is known about the way plants respond to environmental changes.
“There is a growing consensus that it is one of the most important areas that needs development for plant science and Agronomy,” Cademartiri says. “If we want to improve our crop yields, we need to learn how plants respond to very complex environmental cues.”
He says the reason we don’t yet know more about the subject is, in part, because of a lack of tools available for these precise kinds of experiments. High-level techniques have long existed to study small single- or multi-celled organisms, but plants present a problem in that they start out tiny and grow much larger throughout the time of study. Greenhouses work well for large studies that require all plants to have a homogeneous external environment (the same level of heat and humidity, for instance, among other factors). But imagine a plant experiment in which scientists might need to set up 100 plants in 100 different controlled environments, both above and below the soil level, with each setup allowing enough room for the plant to grow, and you start to get a sense of the problem.
Existing microfluidic technologies allow scientists like molecular biologists to control test environments with the precision of a millionth of a meter, but those systems can be very difficult and expensive to scale up for plant research.
Transparent Lego bricks present a happy medium, in that they are affordable but create environments precise enough for serious study, as Cademartiri and his team learned when they began to investigate the idea.
The researchers chose off-the-shelf transparent Lego pieces, which can be purchased individually directly from Lego's Website, put them in an autoclave for sterilization, then used the pieces to build rectangular containers to hold the gel or other soil substitute. The containers can be built to varying sizes to accommodate different plant sizes or root types. When an experiment is over, the pieces can be broken down, cleaned and used again.
Doctoral student Kara Lind, another author of the study, worked on ways to ensure Lego bricks could hold the transparent gels that are used as soil substitutes to allow researchers to easily see root changes, the Iowa State News Service reported. She also worked out ways to create specific chemical gradients within the structures, to see how plants react to different chemicals, be they toxins or nutrients.
The result: “It turned out that Lego performed a lot better than we thought, for a couple of reasons,” Cademartiri says.
For one, a “transparent Lego is made of polycarbonate, so that means it can be sterilized, which makes it ideally suitable for biological work," he says. The bricks are also chemically inert, so they won’t react with surrounding materials and potentially spoil experiments.
The team aims to continue to develop Legos as a platform and tool set for serious plant study, in the hopes that other scientist will find the iconic bricks useful in their own research.
Cademartiri says it’s too soon to tell to what extent scientists will or won’t take up Legos for plant study, but he is optimistic. Educators have long been using Legos in classrooms, and the company's Mindstorms robotics line, aside from being used to help build artificial bones, have also been used by researchers at the University of Vermont to create robots that change their shape to "learn" how to walk. So it's at least likely that Lego bricks will continue to find an occasional home in research laboratories as well as the toy box.
“What we did was to force ourselves to create the simplest, cheapest, most convenient, and capable tools that we could devise,” Cademartiri says. “So, we’re hoping that other scientists will find them useful, and we think they will.”