ADDFab Prints Rhizotrons

Don’t know what that is, read on …

Rhizotron is a laboratory constructed underground, or in this case on a lab bench, in order to study the soil and its interactions with plants and animals. They are typically equipped with a central corridor with viewing windows into the soil on either side.

Biology graduate and undergraduate students, Greg Gregory and Emil Mah (Hazen lab), partnered with ADDFab director Dave Follette to create a scaled down rhizotron that works under a microscope. Up to that point Emil was making these rhizotrons by hand–each one taking a very long time to make. One bench over Kristen DeAngelis, associate professor in microbiology, recommended that they contact ADDFab, as they had just printed something for their lab, and were very happy with the outcome. So together they drafted the design, and contacted Dave and his undergraduate student, Noah Zilberberg to work on a prototype.

 

The requirements were it needed to hold laboratory soil between double-wide microscope slides so the roots could be observed as they grew. After prototyping multiple designs, the final product is 3D printed by SLS from white nylon-12 polymer and then dyed black.  To block the light and encouraging root growth along the glass, the design also incorporates two removable black plastic laser cut panels. These custom fabricated rhizotrons allow visualization of complex root structures in an environment that more closely resembles nature. By using a bioluminescent gene reporter system, they are able to investigate the effects of soil microbes on gene expression in the roots as well as changes in root architecture.

 

Why is this important? Terrestrial plants represent a major part of the carbon cycle as well as being a large carbon sink. Plant roots especially, are crucial to understand in respect to the carbon cycle because of their interactions with soil microbes which also represent a major part of the carbon cycle. “By developing a custom rhizotron system, coupled with our bioluminescent reporter system, we are able to visualize in real time some of these plant-microbe interactions, allowing us to investigate novel questions.” Greg Gregory

Emil will be working in the Hazen lab over the summer. Noah is staying on for the +1 master’s program before heading out into the additive manufacturing industry.

“Working in a state of the art building like this is such an incredible experience as an undergrad. Specifically working with ADDFab has been really great for us. It saves me a lot of time not having to build things by hand. The facility has such incredible technology that they can make these rhizotrons for us that are so precise like the little cuts where the microscope slides are placed, fit perfectly. It has really progressed our research.” Emil Mah, Biology ‘23

“Working in ADDFab has been a really great experience. Starting with the summer internship program, and working through the academic year. I have ained a lot of experience using the state-of-the-art machines available in the facility, to working on design projects with faculty and outside companies. People would come to us with this thing being held together with string and glue, asking can you make it better, more efficient? Dave and I would come up with a design, and then fabricate it–sometimes even the next day. It was fun to see people’s reactions to having a solution to their problem, almost immediately!” Noah Zilberberg, Mechanical and Industrial Engineering ‘22