Designing 3D-printed wheat starch cryogels: Effect of geometry on mechanical performance

Cryogels, porous materials obtained by freeze-drying, are used for various food and biomedical applications due to their interesting material properties. The fracture behaviour of 3D-printed cryogel designs as function of structural parameters such as the infill pattern and the number of outer perimeters, was evaluated by performing uniaxial compression with digital image correlation (DIC) analyses. Both structural parameters influence the mechanical performance of the cryogels, with the infill pattern being the dominant factor. A triangular infill pattern with two outer perimeters gave the highest specific modulus, while a rectilinear infill pattern gave the highest energy absorption capacity. Compression tests revealed that a thinner outer wall gave more ductility. To demonstrate potential applications of 3D-printed wheat starch cryogels, we designed and assembled a partially edible glider which showed gliding stability. Our research shows that edible macroporous structures with tuneable mechanical properties can be manufactured by varying the geometrical design through 3D printing. These structures can potentially replace non-edible materials for various applications. • Mechanical properties of 3D-printed cryogels can be tuned. • Infill pattern significantly influences mechanical properties of 3D-printed cryogel. • Triangular patterns best in specific modulus and rectilinear in energy capacity. • A thinner outer wall gives more ductility. • 3D-printed cryogels can replace non-edible materials for various applications.