Additive manufacturing–facilitated blow molding for functional thin-walled polymeric structures

Abstract

Thin-walled structures capable of large, reversible deformation are key to multistability, origami, kirigami, and soft robotics. However, conventional fabrication techniques—including 3D printing, casting, and laser cutting—suffer from low durability, complex workflows, and restricted geometric freedom, hindering repeatable production. We introduce additive manufacturing–facilitated blow molding (AM-BM), combining the design flexibility of additive manufacturing with the robustness of blow molding. Replacing metal molds with additively manufactured resin ones enables rapid, low-cost fabrication of thin-walled components with tunable geometry and controllable wall thickness out of diverse thermoplastics. The thickness control allows thin-walled components to function as rigid load-bearing elements or compliant hinges. Demonstrations include multistable structures with geometry-controlled reconfigurability; origami and kirigami structures with extensive design freedom and uniform mechanical properties; and soft actuators and robots with ultrahigh load-to-weight ratios and rapid response. AM-BM offers a versatile, scalable route to thin-walled structures combining geometric freedom, mechanical functionality, and efficient production.