Pneumatic Biomaterials Deposition

Structural hierarchy and material organization in design is traditionally achieved by combining discrete homogeneous parts into functional assemblies where the shape or surface is the determining factor in achieving function. In contrast, biological structures express higher levels of functionality on a finer scale through volumetric cellular constructs that are heterogeneous and complex. We focus on water-based materials and demonstrate additive manufacturing of diverse constructs associating shape-informing variable flow rates and material properties to mesh-free geometric primitives. This enables virtual-to-physical control where structural, mechanical and optical gradients are achieved through a seamless design-to-fabrication tool with localized control. The tool is an enabling technology that combines a positioning robotic arm and a multi-syringe multi-nozzle pneumatic deposition system. It can extrude materials with viscosities ranging from 500cPs to 50.000cPs at room temperature such as; hydrogels, gel-based composites. Certain types of clays, organic pastes, resins, and polyvinyl alcohols could also be integrated. The materials present visco-plastic or visco-elastic behaviors inside airtight barrels and undergo slow curing from pastes to solids at room temperature. The platform has the capacity to structure such materials in local, regional and global organizations providing functionally-graded structural and optical properties to the overall construct. The work provides an opportunity to research large-scale digital manufacturing of sustainable, biocompatible and biodegradable structures for a variety of applications such as: tissue scaffolds, prosthetic wearable devices, or temporary architectural structures.