A maker uses a shear-thinning support bath to print an epoxy benchy, overcoming traditional FDM limitations.

Imagine a maker crafting a tiny, delicate object, like a benchy, using a 3D printer that doesn’t just melt plastic but manipulates a gel bath to hold it in place. This is the world of embedded 3D printing, where the printer’s nozzle slices through a gel that flows like liquid but solidifies like a stone. The result? A benchy that holds its shape, even after hours of printing.

The technique, described in Hackaday, relies on a material science trick called shear-thinning: a gel that behaves like a solid at rest but flows like a liquid when disturbed. The printer’s nozzle squeezes through the gel, liquefying just ahead of the tip and rejoining as it exits. This allows the printer to extrude liquid materials like epoxy without the usual issues of melting points or flow.

The maker, Riley of Riley’s Lab, tested this method by printing a benchy from silicone and epoxy. The gel bath contained the liquid, yet flowed as the nozzle passed, creating a stable structure. For a test, they even printed a tardigrade model from cream cheese, which held its shape well. The success of this approach highlights the potential of embedded 3D printing to push the boundaries of what’s possible.

The gel bath isn’t just a gimmick. It solves the “where does the extrusion go” problem, but also addresses the second hurdle: FDM printers struggle with liquid materials. By replacing the extruder with a syringe pump, the printer can extrude anything from a syringe, not just filament. This opens up new possibilities for 3D printing, from bioprinting to custom materials.

The technology isn’t new, but the application is groundbreaking. Commercial versions exist, and research is ongoing. The maker’s work, documented on Hackaday, shows how this method could revolutionize 3D printing by enabling the creation of complex shapes that traditional methods can’t achieve.

The implications are vast. With this technique, 3D printers could print objects that are both functional and intricate, from medical implants to artistic designs. The ability to extrude liquids without relying on thermoplastic filament opens doors for new industries. As the maker’s work demonstrates, the future of 3D printing is not just about speed or resolution but about pushing the limits of material science.