Investigation of the Programmable Deformation of 4D‐Printed Cassava Starch‐Based Gels: Applications in Baked Foods

ABSTRACT 4D printing, an evolution of 3D printing, introduces the dimension of time to enable printed structures to undergo transformations when exposed to external stimuli. This capability offers unlimited creative potential for personalized cuisine, such as creating foods with shape‐shifting properties. This study developed 3D‐printed bilayer cassava starch‐based hydrogels to achieve programmable deformation during baking as a thermal stimulus. Aligned printing paths (0°/0°) maximized bending angles. Reducing nozzle diameter and increasing aspect ratio amplified deformation, while higher infill density caused an initial rise and then decline in bending. Elevated baking temperatures accelerated early dehydration but induced surface hardening, limiting later deformation. Furthermore, the incorporation of butter reduced the final bending angle of the printed products, whereas the addition of white granulated sugar exhibited the opposite trend. Ultimately, through fine‐tuning printing parameters and ink composition, the products achieved programmable deformation behaviours, such as the automatic “wrapping” of flat boxes and petals, as well as the automatic “curling” of octopus tentacles. This study provides new insights for the precise design of starch‐based baked foods in 4D printing.