From Espresso to Eco-Brick: How Coffee Waste Fuels 3D-Printed Design

For centuries, people used coffee grounds to read the future. At I'mnovation-Hub, we prefer science over superstition—but we also believe that a more sustainable future could well lie in the coffee grounds we discard each morning. That is the thinking behind a new line of research from the University of Washington, where scientists are exploring how to turn organic waste into biodegradable packaging and new building materials. The key ingredient? Mycelium—the underground root-like structure of fungi.

Mycelium is a dense network of fungal threads that grows naturally beneath the soil. When fed with organic waste—such as sawdust, cardboard, or coffee grounds—it forms lightweight, fibrous structures that, once dried, behave like polystyrene or even leather. What was once a biological curiosity is now a rising star in the search for sustainable alternatives to plastics and synthetic foams, thanks to its low carbon footprint and natural biodegradability.

From mushroom to material: merging mycelium with 3D printing

At the University of Washington’s Center for Digital Fabrication, researchers have taken this concept a step further by integrating mycelium with 3D printing. Unlike conventional techniques that rely on rigid moulds to shape fungal growth, this method prints flexible scaffolds that fungi can colonise, resulting in compostable components with tailored geometries.

The process begins with a gel-like ink that includes nutrients and organic waste—mainly coffee grounds and rice flour. This printed structure guides the growth of the fungi, which spread along the patterned lines. Within five days, the mycelium takes over the entire form, which is then dried to halt further growth and lock in its final shape.

This method offers a scalable and adaptable way to produce biodegradable objects—and it could even enable localised manufacturing. Any community with access to organic waste and a basic 3D printer could produce sustainable materials on demand. And once the item has served its purpose, it can be safely composted or left to biodegrade.

What makes 3D-printed mycelium especially compelling is its versatility. Depending on the fungus strain and the chosen substrate, the resulting materials can be rigid, elastic or moisture-resistant. This adaptability opens doors for applications across packaging, industrial design, construction—and even fashion. Some of the prototypes include protective packaging for glassware and decorative vases.

 

 

Mycotecture: the precedent set by the construction industry​

While this new research advances additive manufacturing, the use of mycelium as a construction material has a longer history. In architecture, the concept of “mycotecture” has inspired experimental designs where fungi replace bricks. These “living bricks” are grown, not fired, using agricultural waste such as corn husks or hemp stalks.

One standout example is the work of architect Phil Ross, a pioneer in fungal-based building systems. In partnership with various institutions, he has developed interlocking blocks suitable for temporary shelters, acoustic panels or decorative features. As outlined in this article, mycelium holds promise not only as a plastic alternative but as a low-impact building solution in a sector known for heavy resource use.

Beyond its ecological credentials, mycelium is easy to grow, requires little energy, and can adapt to diverse environments without extensive infrastructure. Its main drawbacks? Growth takes time—and the final product is typically less durable than traditional materials.

​This bench is a 3D-printed work of art

Of course, 3D printing continues to evolve far beyond fungi. Across sectors, additive manufacturing is enabling innovative shapes and structures for buildings and public furniture. One eye-catching example, unrelated to mycelium, is a sculptural bench made using contour crafting with cement.

Thanks to this technique, the bench features a sweeping, organic design that blurs the line between functional furniture and public art. Installed in the courtyard of Seville’s Puerta Barqueta housing estate, the piece was printed in just twenty minutes and set overnight before being placed in its final location the next day.

 

 

Source:

• University of Washington