The latest advancements in 3D printing tend to focus on space-age technology: computer components, custom toys, laser-based nanotechnology, and even rocket fuel. But Ajay Malshe wants you to think of your next snack. As part of an Intro to Additive Manufacturing course, Malshe challenged his students to design a 3D food printer to deposit almond butter – but he gave them some significant constraints.

“It needed to be just six to seven parts, and completely mechanical, with no need for electricity,” said Malshe, the R. Eugene and Susie E. Goodson Distinguished Professor of Mechanical Engineering. “This teaches frugal engineering, which uses simple principles to achieve the highest goals.”

He and Salil Bapat (Research Scientist who is helping to teach the class) also requested that they print a shape: a Purdue “P.” Why is this important? “Food is a holistic experience,” said Malshe. “The more interesting it is, the more likely people will benefit from it and enjoy it together. Plus, it helps students to retain the knowledge they’ve gained, even years from now. They’ll always remember the time they printed a ‘P’ with almond butter!”

The four teams of students approached the problem in four different ways. One team focused on the print head, using a thumbscrew to extrude the “ink.” Another used a dot-matrix housing, which enables users to print numerous shapes in addition to the “P.” The third team used a pastry bag to hold the almond butter, ensuring that the food substance never comes into contact with the machinery, which simplifies cleaning. And a fourth team built a simple multi-axis tray mechanism, which one user can trace into a pre-built “P” template while another user dispenses the almond butter.

“The last team thought their design was too simple,” said Malshe, “but I told them it’s actually their most unique feature. It looks like a colorful toy, and it’s simple enough for a child to use. So it creates an experience that the entire family can share.”

To be fair, there are several 3D food printers already commercially available. Malshe used the “frugal engineering” exercise as a jumping-off point to promote the basics of manufacturing, while addressing societal inequities like hunger – which was magnified during the COVID pandemic. “On a college campus like Purdue, there are many students who are food insecure,” he said. “Many of their classmates may not even be aware that their fellow students are experiencing food insecurity.”

Several of Malshe’s students are working on independent 3D-printed food projects, with the eventual goal of building some sort of vending or dispensing machine that sits in a student lounge or other common area. Rather than face the stigma of a food pantry, students can dispense healthy snacks for free from the machine, customizing them with different shapes, colors, or flavors. This makes the process feel less like a handout, and more of an empowering and positive shared experience.

“We need to instill in our students the mindset of using the highest technology to achieve equity,” said Malshe. “Even simple machines like these can help to channel the students’ ingenuity for an impactful purpose.”

Source: Ajay Malshe, amalshe@purdue.edu

Writer: Jared Pike, jaredpike@purdue.edu, 765-496-0374