Industrial engineering doctoral student uses 3D printing to build robotic arm

UNIVERSITY PARK, Pa. — While many students spent their summers at the beach or binge watching Netflix, industrial engineering doctoral student Rakshith Badarinath and Shu Shu Wang, who graduated in the spring with her master of science degree in industrial engineering, built a robotic arm.

Unlike traditional robotics that use pieces made of metal, the partners used 3D printing. The project began as a topic for Wang’s thesis. When she decided to focus on 3D printing she reached out to her friend Badarinath, whose research is focused on additive manufacturing, for help.

Badarinath had been interested in manufacturing since he was a child.

“You know those shows on the Discovery Channel, where they show the factories of cars and other items? I loved watching those,” Badarinath said.

His childhood interests led him to pursue a bachelor’s degree in electrical engineering from Siddagana Institute of Technology in India. When deciding on a graduate program, Badarinath wanted to not only continue learning about manufacturing but also how to optimize the process. During his first semester at Penn State, he was introduced to 3D printing in one of his courses. Since then one of Badarinath’s projects has involved working with faculty members in the Harold and Inge Marcus Department of Industrial and Manufacturing Engineering to convert machines in the department’s Factory for Advanced Manufacturing Education (FAME) lab into 3D printers.

Badarinath and Wang were brought together by their adviser, Vittal Prabhu, who suggested the two work together. After numerous meetings, Prabhu helped the students nail down an idea for the project.

The focus of Wang’s thesis was comparing the results after using different 3D printing processes to create an object. Through open-source software online, Badarinath was able to purchase the plans and coding for a robotic arm called “MeArm.”

“We didn’t want to make something that is a play thing, like a toy or figurine,” said Badarinath. “We wanted it to be functional, to have an actual use in industry.”

There are currently seven processes for 3D printing, and FAME is equipped with three. The first process Badarinath and Wang used was fused depositing modeling (FDM). FDM is probably what you think of when you think 3D printing. An object is created by the overlaying of numerous thin layers of melted plastic.

“Like icing a cake,” as Badarinath described it.

The second process the partners studied was material jetting. This process is similar to an inkjet printer; however, instead of drops of ink distributed onto paper, the printer deposits — or jets — melted plastic onto a build tray. During the printing multiple nozzles jet the melted material at once. Similar to FDM, multiple layers build up to create the object.

After printing the parts for the arm using both processes, the pair compared FDM and material jetting to determine which was the best option to meet their goals for the project.

“We were focused on seeing if 3D printing would change the functionality of the arm,” Badarinath said. “Different processes can render different results. We wanted to know which was the most accurate and if inaccuracies would alter the end effect for the arm, which is extending and then gripping something.”

After two months of research, Badarinath and Wang concluded material jetting was the best choice for manufacturing the robotic arm. In the reproduction of the arm, material jetting proved to be the most precise and had the best resolution of the two processes.

Since the completion of their project over the summer, Wang graduated with her master's degree. Badarinath still has three years left in his program and has already moved on to a new project. 

“The arm was really just a side project for me, something fun,” he said. “I am now focusing more on my personal project, which is using industrial robots for 3D printing.”