A group of creative engineers from the University of Washington recently introduced a plastic alternative that utilizes a mix of used coffee grounds and 3D-printed mycelium biocomposites to create intricate, water-resistant packaging. The research could help reduce waste and provide a sustainable solution to today’s plastic woes. Here’s everything you need to know.
Plastic Waste
Plastic waste is a major concern that remains a main focus for environmentalists and researchers alike. There are currently millions of tons of plastic waste in the world and ocean. Worst of all, studies predict an increase in plastic waste yearly for the foreseeable future.
As these harmful products break down, they create macro plastics that make their way into the food chain and, eventually, you. Microplastics aren’t harmful in small doses. However, as their volume increases, so do their side effects.
BioPrinting Solutions
The term ‘bioprinting’ refers to additive manufacturing using living organisms. This 3D printing sector continues to expand across multiple industries. In the future, bioprinters could be used to help space travelers heal their organs and other vital body parts. For now, they could hold the key to reducing waste.
Details of the Study
Recognizing the need for viable, sustainable plastic alternatives, a team of engineers published the study “3D-Printed Mycelium Biocomposites: Method for 3D Printing and Growing Fungi-Based Composites in 3D Printing and Additive Manufacturing.”1 The study delves into using food waste, specifically coffee grounds, to create an ideal spot for fungus to grow.
Source – University of Washington
Coffee grounds were chosen for a few key reasons. For one, billions of pounds of coffee grounds are discarded every year, as the majority of coffee isn’t absorbed during the coffee-making process. Notably, while coffee ground waste has many nutrients that fungi like mushrooms can utilize to grow, they are not naturally sterile despite being a low risk for contamination. To ensure sterility, the researchers treated the substrate with alcohol wipes and maintained clean handling protocols to prevent unwanted microbial growth.
Skin Formation
The first step that mushrooms take when growing on a new substance is to form Mycelium skin. This skin operates like a root system, binding the mushrooms to the surface and each other.
Mycelium is fully biodegradable and does not harm the environment. Impressively, it grows quickly and provides significant water resistance without showing signs of deformation. Once the proper Mycelium was selected, the engineers figured out how to form the Mycelium into shapes.
Mycelium skin is a living material that researchers proved can sense both light and touch stimulations. It has been used to create electrical components and modular architectural designs and has seen research in self-growing robots in the past. Now, it could help to reduce plastic waste.
Mycofluid
The decision was made to create a paste called mycofluid. The Mycofluid formulation consists of:
- 54.9% spent coffee grounds – serving as the primary recycled biomass
- 13.7% brown rice flour – providing carbohydrates for fungal growth
- 5.5% ground grain spawn – introducing the fungal spores
- 1.1% xanthan gum – acting as a viscosity modifier and binder
- 24.7% water – maintaining moisture for mycelium development
The inoculated mixture is whipped together until it’s smooth enough to be expelled through a special 3D printer extruder.
Purpose-Built Nozzles
Engineers created a purpose-built 3D printer nozzle that integrated a layer extruder nozzle designed specifically to handle the thick paste. The new 3D printer head was specially designed to leverage the Jubilee 3D printer that was also created at UW’s Machine Agency lab.
The new system included an upgraded paste-holding system. This system can hold a liter of paste and can be expanded for larger applications when needed. Notably, the storage and nozzle were built to handle different types of materials, reflecting the engineer’s goal to provide multiple solutions to the plastic waste problem.
Testing Phase
The new system was tested by printing several items, including a Moai statue, packing materials, three pieces of a vase, and other items. Some of the items, like the butterfly coffin, had multiple pieces that linked together.
The engineers printed the designs using a proprietary printer. The shapes were then left in a sterile chamber for 10 days. This approach enabled the spores to form strong mycelium. After ten days, the objects were removed, and their durability was tested.
Notably, if the items remained in the sterilization chamber longer they would have continued to sprout into mushrooms. To prevent further growth, the mycelium-covered pieces were removed and completely dried.
Test Results
The results of the experiment showed promise. For one, the Mycelium successfully fused separately printed pieces together, demonstrating that the packaging material can be produced in modular sections and still achieve strong structural integrity. This means the packaging material can be used for intricate designs and short-batch processing. Testing showed that the mycelium biocomposite exhibited mechanical properties similar to expanded polystyrene foam, commonly used in packaging. While not necessarily stronger than Styrofoam, it offers comparable durability while being fully biodegradable. According to research documentation, it displayed a density that was similar to high-end cardboard.
Water Resistance
Researchers conducted a 24-hour water absorption test, comparing colonized and uncolonized mycelium biocomposites. The colonized samples exhibited only 7% absorption, retaining their shape and structural integrity, whereas uncolonized coffee-based composites fully disintegrated in water.
It also offered promising levels of durability while being fully biodegradable. Additionally, it can be formed more easily and with less expenses.
Potential Market Benefits
This research brings many benefits to the market. For one, there’s a strong need to find plastic alternatives. The pollution caused by this waste has hit dangerous levels. To prevent damaging ecosystems beyond repair, a solution needs to appear. This alternative to plastics is environmentally safe and affordable.
Additionally, it provides more than just an alternative to plastic. Researchers seek to expand this technology to create styrofoam alternatives as well. Combined, these packaging materials could help to reduce global pollution and inspire additional forms of sustainability.
Intricate Designs
One of the main benefits of this style of packaging is its flexibility. The mycelium fuses separately printed pieces together, making one durable packaging that can withstand impact and moisture. Additionally, it can support complex and customized one-time requirements without the need to expand manufacturing processes.
Small Batch Manufacturing
The 3D-printing process for mycelium biocomposites is well-suited for custom, small-batch production, particularly for packaging fragile or uniquely shaped items. Unlike traditional molded mycelium products, this method allows businesses to produce custom-fit designs without the need for molds.
Hurdles to Overcome
There are multiple hurdles that the engineers still need to address for their new packaging method to become a mainstream solution For one, it requires basic sterilization of food waste to support the growth of the mycelium used to create the Mycofluid. This requirement will limit large-scale usage of this method.
However, as researchers expand the material they use to include all types of food waste, they hope to find a solution that is both readily available and in need of removal from the environment. Combining these requirements ensures that this alternative does not create more waste while helping to solve the plastic problem.
Companies Leading the BioPrinting Market
The bio-printing sector continues to expand as more materials and printing methods emerge. Today’s bioprinters can create entire homes using dirt and other materials.
Additionally, some bioprinters can create human organs and other vital treatments to save lives. These devices continue to expand in their capabilities and use case scenarios. Here’s one company that has established a reputation for innovative solutions in the bioprinting sector.
United Therapeutics (UTHR -2.05%) entered the market in 1996. Its founder, Martine Rothblatt, is a well-known entrepreneur who started multiple firms, including SiriusXM. Notably, the company was formed after his daughter became terminally ill.
Years later, United Therapeutics is a leader in lung disease treatments and organ manufacturing. Recently, the company entered the bioprinting arena with the acquisition of Miromatrix.
United Therapeutics Corporation (UTHR -2.05%)
United Therapeutics could easily benefit from an influx in demand within the bioprinting sector due to new applications like packaging requirements. The company already offers reputable bio-printing products and is regarded as an industry leader. As such, those seeking an established bioprinting stock should do further research into UTHR.
3D-Printed Mycelium Biocomposites – Endless Possibilities
The concept of utilizing items like coffee waste and fungus to create durable packaging deserves a salute. This concept, while still in its fledgling stages, could one day lead to organic packaging materials. Humankind needs plastic alternatives, and it may turn out that more than one solution is the answer. As such, this research could be seen as a valuable piece of that puzzle.
Learn about other cool Additive Manufacturing projects now.
Study Reference:
1. Luo, D., Yang, J., & Peek, N. (2025). 3D-printed mycelium biocomposites: Method for 3D printing and growing fungi-based composites. 3D Printing and Additive Manufacturing. https://doi.org/10.1089/3dp.2023.0342