Team 3D prints edible QR codes with food printer

A research team from the Singapore University of Technology and Design (SUTD) has developed a method for producing and designing customized food products.

The team published their findings in the journal Future Foods under the title “Multi-material direct ink writing 3D food printing using multi-channel nozzle”.

Some repurposed food sources such as okara (soybean residue), orange peel and insect protein have met with little enthusiasm due to their appearance and origin. By adjusting the printing parameters, researchers can integrate edible and nutritious ingredients from these unusual sources and construct a visually appealing meal.

For everyday life, this offers a personalized and sustainable way to ensure daily nutrition. At the same time, people with eating disorders or swallowing difficulties (dysphagia) can customize their meals and improve their eating habits.

“Printing food in 3D enables the customization of nutrients, the creation of aesthetically pleasing meals, and the modification of food texture to suit individual dietary needs,” explains principal investigator Michinao Hashimoto, an associate professor at SUTD looking into combining the use of design and technology in research.

A common approach uses multiple nozzles to hold and dispense different food ingredients, much like a box of crayons. This method requires careful machine design and nozzle adjustment, resulting in discontinuous interfaces and long printing times.

Prof. Hashimoto and his team prefer a different approach inspired by microfluidics. With two inlets and one outlet, this approach reduces the complexity of changing nozzles by combining the food pipelines before the printing stage.

“Our technology can be used to 3D-print foods consisting of multiple materials without compromising the printed structures and appearance,” said Dr. Lee Cheng Pau, the lead researcher of the current study. “It can be applied in creating meals tailored to individual dietary needs, aesthetically pleasing dishes, and interactive food experiences such as edible QR codes.”

However, combining different food inks through interfaces is not trivial. Backflows into the ingredient inlets occur with liquids with different rheological properties – such as flow behavior and viscosity. To solve this problem, the researchers expanded the outlet port of the Y-connector in the printer to accommodate food inks with high flow stress, which require more force to extrude. This change provides less resistance to flow and prevents the ink from entering the wrong channel in the printer.

In addition, the researchers took into account the delay in the ink change and implemented an offset for the printing algorithm. With their clever design, the team was able to demonstrate seamless and continuous printing between inks with different rheological properties, with minimal reflux. To demonstrate the performance of their system, they printed the SUTD logo and a fully functional QR code using different milk inks.

In the future, the team hopes to further optimize the design and technology to integrate more inlets and drive commercial scalability.