What Happened?
Recent developments in the field of additive manufacturing have been highlighted by a comprehensive review published in Nature, focusing on non-planar additive manufacturing with hydrogels. This review synthesizes recent advances in flow control and toolpath strategies that enable printing beyond traditional planar layers, opening new pathways for complex 3D structures with enhanced functionalities.
Why It Matters
Non-planar 3D printing breaks away from the conventional layer-by-layer approach, allowing for curved, multi-axis, and volumetric deposition. When combined with hydrogels—a class of soft, water-rich materials widely used in biomedical applications—this technique promises to revolutionize areas such as tissue engineering, soft robotics, and custom biomedical devices. The ability to precisely control flow and toolpaths in three dimensions enhances structural integrity, surface finish, and functional gradients that are difficult or impossible to achieve with planar printing.
Technical Context
Traditional 3D printing typically operates on a fixed XY plane, depositing material layer by layer along the Z-axis. Non-planar 3D printing involves dynamically adjusting the print head orientation and path to deposit material on curved or angled surfaces, requiring sophisticated motion control and path planning algorithms. Hydrogels present unique challenges due to their rheological properties—viscous, shear-thinning, and often sensitive to extrusion conditions. The reviewed research focuses on strategies to optimize flow rates, nozzle trajectories, and curing methods to maintain shape fidelity and mechanical performance during non-planar printing.
Key technical aspects include:
- Flow Control: Managing extrusion pressure and speed to accommodate the changing nozzle orientation and gravity effects on hydrogel deposition.
- Toolpath Strategies: Designing multi-axis trajectories that minimize defects, improve layer adhesion, and enable complex geometries without support structures.
- Material Behavior: Understanding hydrogel viscoelasticity to predict and compensate for deformation during and after printing.
Near-Term Prediction Model
Given the current state of research and early pilot implementations, non-planar hydrogel 3D printing is progressing from experimental setups toward pilot-stage applications in specialized biomedical manufacturing.
What to Watch
- Emergence of commercial multi-axis 3D printers optimized for hydrogel materials.
- Development of standardized toolpath algorithms tailored for soft materials.
- Integration of real-time feedback systems for flow and curing control.
- Expansion of application domains beyond biomedicine, such as soft electronics and customized wearables.