Mycelium Packaging Foam Strength Test

ISEF Category: Environmental Engineering

Subcategory: Recycling and Waste Management  ·  Difficulty: Intermediate  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

Plastic foam protects packages, but it sticks around for decades. Mycelium-based foam uses mushroom roots to bind waste materials into a lighter, greener shape. You can test whether coffee grounds, sawdust, or cardboard makes the strongest version. That turns a messy waste stream into a materials science project.

What Is It?

Mycelium is the root-like network of a fungus. Think of it like nature’s glue. When you grow it through loose plant waste, the strands spread through the material and lock it together into a solid foam-like form.

Your project asks a simple question with a real materials science answer, which waste feedstock makes the best packaging foam? Coffee grounds, sawdust, and shredded cardboard each have different fiber size, moisture behavior, and packing density. Those differences can change how well the mycelium grows and how strong the final block becomes.

Expanded polystyrene, or EPS, is the white foam used in many shipping boxes. It is light and cushions well, but it creates disposal problems. Your project compares a bio-based alternative to a common benchmark, so you are not just making a cool object. You are testing whether a greener material can compete on strength.

Why This Is a Good Topic

This topic works well because you can change one input, the substrate, and measure one output, compressive strength. That makes the experiment clear and testable. It connects to packaging waste, recycling, and sustainable materials, so the real-world problem is easy to explain. You can learn how to design controls, compare materials, and turn raw test data into a fair benchmark against EPS.

Research Questions

• How does the feedstock type, coffee grounds, sawdust, or shredded cardboard, affect the compressive strength of mycelium foam?
• What is the effect of substrate particle size on the density and strength of the finished mycelium foam?
• Does mixing two waste feedstocks produce stronger foam than using one feedstock alone?
• To what extent does drying method change the final strength and mass of mycelium packaging foam?
• Which feedstock gives the best strength-to-weight ratio compared with expanded polystyrene?
• How does the growth time of the mycelium influence the compressive performance of the foam?

Basic Materials

• Coffee grounds, dried and free of large debris.
• Sawdust, untreated hardwood or softwood.
• Shredded cardboard, plain corrugated cardboard with ink removed if possible.
• Mushroom spawn or mycelium starter culture from a reliable supplier or school source.
• Small molds for forming foam blocks.
• Digital kitchen scale with 0.1 g accuracy.
• Ruler or digital calipers.
• Notebook or spreadsheet for recording mass, size, and test results.
• Smartphone camera for documenting samples.
• Books, weights, or a simple force gauge setup for basic compression comparison.
• Drying rack or clean drying area.
• Gloves and mask for handling dry dust and spores.

Advanced Materials

• Universal testing machine or force gauge with compression fixture.
• Vernier calipers or digital thickness gauge.
• Drying oven or controlled drying chamber.
• Analytical balance.
• Incubator or temperature-controlled growth space.
• Sterile mixing tools and containers.
• Petri dishes or agar plates for checking contamination.
• Microscope or low-power inspection tool for observing mycelium coverage.
• Image analysis setup for measuring pore structure.
• Density measurement tools for standardized material testing.

Software & Tools

• Google Sheets: Organizes measurements, calculates averages, and builds comparison charts.
• ImageJ: Measures pore size, surface coverage, and sample dimensions from photos.
• Python: Helps you analyze strength-to-weight trends and test whether differences are real.
• R: Runs statistical tests and makes clean plots for material comparisons.
• PubMed: Helps you find review articles on mycelium composites and biodegradable foams.

Experiment Steps

1. Define the exact performance metric you will compare, such as compressive strength, strength-to-weight ratio, or both.
2. Choose one variable to change first, such as substrate type, while keeping mold shape, growth conditions, and drying method constant.
3. Plan a control group and a benchmark group so you can compare mycelium foam with a known material like EPS.
4. Design a measurement method that gives numbers, not just visual impressions, and decide how you will repeat each sample.
5. Build a data table for mass, dimensions, density, and failure load so you can compare samples fairly.
6. Decide which graph and statistical test will answer your research question without mixing together different variables.

Common Pitfalls

• Using damp or unevenly prepared feedstock, which changes growth and makes samples hard to compare.
• Letting mold or other contamination spread, which can ruin the mycelium and distort strength results.
• Comparing blocks with different shapes or densities, which makes compressive data unfair.
• Relying on a hand squeeze test, which gives subjective results instead of measurable strength values.
• Forgetting to standardize drying, which leaves extra water in some samples and makes them seem weaker or heavier than they are.

What Makes This Competitive

A strong project goes beyond making one foam sample and asking which one feels firmer. You need clean controls, repeat trials, and a fair benchmark against EPS. You also need a measurement plan that converts sample shape, mass, and force into a real material metric, like strength-to-weight ratio. If you add a second analysis layer, such as pore structure, density, or failure mode, your project starts to look like real engineering research.

Project Variations

• Test whether mixing coffee grounds with cardboard creates a better strength-to-weight ratio than either waste alone.
• Compare mycelium foam made from fine versus coarse sawdust to see how particle size changes compression behavior.
• Measure how surface texture or internal pore size relates to strength by using ImageJ on sample photos.

Learn More

• USGS Science in Recycling and Materials: Search the USGS site for background on waste materials, reuse, and resource flows.
• NOAA Marine Debris Program: Read about plastic waste problems and why alternative materials matter, using the NOAA website.
• NASA Earthdata: Find articles and datasets on materials, waste, and environmental impacts through NASA Earthdata and related pages.
• PubMed: Search for review articles on mycelium composites, fungal biopolymers, and biodegradable packaging materials.
• MIT OpenCourseWare Materials Science: Look for free lectures and notes on material properties, composites, and testing methods.