(Nanowerk Spotlight) A new 3D printer can cook food layer by layer as it prints, using artificial intelligence to design complex edible structures. This integrated system, developed at Hong Kong University of Science and Technology, combines precision infrared heating with AI-driven design tools to address key limitations in automated food production: maintaining food safety during printing and creating intricate shapes without requiring technical expertise.
Automated food production faces unique challenges compared to manufacturing with traditional materials like plastics or metals. Food must be heated properly to ensure safety, yet maintaining the intended shape during cooking proves difficult. Current 3D food printers operate in two separate steps – first printing cold food paste, then transferring it to an oven or fryer. This approach often leads to deformed shapes and increased contamination risks as the food moves between machines.
The new system integrates these steps using a specialized infrared heater made from laser-treated polyimide film, known as laser-induced graphene (LIG). This ultra-thin heating element provides precise temperature control, with printed food layers reaching 137°C on the surface and maintaining at least 105°C on the sides throughout the printing process, while using just 14 watts of power – a fraction of the 1000-2000 watts consumed by conventional ovens and air fryers.
a). The step-by-step 3D food fabrication process of the printing and in-line cooking device. b). Design features of the integrative 3D food printer. c) The print head unit has an extrusion tubing inlet, extrusion nozzle, and heater holder. d) The external shell of the infrared heater has a cone-shaped design to converge heat transmission to the targeted printing area. e) The schematic diagram of the fabrication of the LIG infrared heater. (Image: Reprinted from DOI:10.1002/adma.202408282, CC BY) (click on image to enlarge)
The researchers demonstrated their printer using starch-based cookie dough. As each layer of dough emerges from the printing nozzle, the infrared heater immediately cooks it, maintaining the exact printed shape while killing harmful bacteria. This immediate cooking prevents the slumping and deformation that typically occurs when printed food items wait to be baked.
Detailed analysis revealed superior results compared to conventional cooking methods. Using scanning electron microscopy, the team observed that infrared-cooked samples maintained consistent internal structure without the dramatic swelling seen in oven-baked items. X-ray imaging showed uniform porosity throughout the food, indicating thorough cooking without compromising structural integrity. Additionally, COMSOL simulations confirmed even heat distribution, showing that heat penetrated only 1-2 mm from the top layer, preventing overcooking of the lower layers.
The system’s food safety advantages became clear through bacterial testing. While conventionally cooked samples showed substantial bacterial growth after 48 hours, infrared-treated items had only 0-6 bacterial colonies at 100°C, compared to over 200 colonies in oven-baked and air-fried samples. This improvement stems from the immediate high-temperature treatment of each printed layer.
The researchers also simplified the design process through artificial intelligence. Instead of requiring users to master complex 3D modeling software, their system accepts simple text descriptions. These descriptions feed into the DALL-E AI system, which generates appropriate 2D images. A custom Python script then converts these images into STL 3D modeling files, making them ready for printing without additional user intervention. A baker could type “gingerbread man with detailed pattern” and receive a complete, printable design within minutes.
Testing demonstrated the system’s versatility. The printer successfully created items with intricate perforated patterns and multiple layers while maintaining precise dimensional accuracy. Beyond cookie dough, it handled various food materials, including vegetable purees and protein-based ingredients, further validating the system’s adaptability to different food types.
The technology’s implications extend beyond simple food printing. The combination of AI design tools and integrated cooking capabilities opens possibilities for automated commercial food production. The system’s energy efficiency and compact size make it practical for restaurants and bakeries seeking to offer customized food items without extensive technical training.
The researchers envision particular value in healthcare settings, where precise control over ingredients and portions is crucial. The technology could enable automated production of specialized diets while ensuring consistent quality and safety.
Their work also demonstrates broader applications for integrated heating in 3D printing. The precise temperature control and energy efficiency achieved through their LIG heating system could benefit manufacturing processes beyond food production.
The integration of AI design capability with real-time cooking represents a significant step toward accessible automated food production. By addressing both the technical and usability challenges that have limited adoption of 3D food printing, this system offers a practical path toward more automated, customizable food service operations while maintaining high standards for safety and quality.
The development signals a shift in how commercial kitchens might approach personalized food production, suggesting a future where complex custom food items can be created safely and efficiently without specialized technical knowledge.
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