Mycelium Packaging Foam Testing and Modeling

ISEF Category: Chemistry

Subcategory: Materials Chemistry  ·  Difficulty: Intermediate  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

Packing foam looks harmless, but it can sit in landfills for ages. Mycelium composites offer a plant-like swap, grown from fungus and waste instead of petroleum. You can test whether coffee grounds help make a foam that is light, strong, and easier to break down. That gives you a real materials problem with a real product target.

What Is It?

Mycelium is the thread-like network that fungi use to grow. If you mix it with a plant waste like coffee grounds, the fungus can bind the particles into a solid block. After growth, you dry and finish the piece, and the final material can act like a foam. Think of it like fungal glue holding a crumbly scaffold together.

This topic is about how the growth recipe changes the final material. If you change the coffee-grounds ratio, the mold shape, or the growth humidity, you may change density, strength, and how fast the material breaks down later. Density means how much mass fits into a given space. Compressive strength means how much squeezing force the material can take before it deforms or cracks.

Why This Is a Good Topic

This is a strong science fair topic because you can change one growth condition at a time and measure clear outputs. You are not guessing about success. You can compare density, compressive strength, and biodegradation across samples and look for patterns. The project connects to packaging waste, sustainable materials, and product design, so your results have a real-world use.

Research Questions

• How does the coffee-grounds ratio change the compressive strength of mycelium biocomposites?
• How does the coffee-grounds ratio change the density of mycelium biocomposites?
• What is the effect of controlled humidity during growth on compressive strength?
• What is the effect of controlled humidity during growth on biodegradation rate?
• To what extent can growth conditions predict mechanical outcomes with a simple machine learning model?
• Which sample geometry gives the most consistent strength-to-density ratio?

Basic Materials

• Oyster mushroom spawn or mycelium culture from a reputable supplier.
• Used coffee grounds, dried and filtered.
• Pasteurized plant fiber substrate such as straw, wood shavings, or hemp hurds.
• Small molds made from plastic cups, food containers, or silicone forms.
• Digital kitchen scale with 0.1 g accuracy.
• Ruler or digital caliper.
• Household hygrometer for tracking humidity.
• Sealable containers or a simple humidity chamber setup.
• Paper towels, gloves, and isopropyl alcohol for cleanup.
• Notebook or spreadsheet for tracking growth and measurements.
• Flat boards or a simple compression setup for comparing samples.
• Camera or smartphone for consistent sample photos.

Advanced Materials

• Texture analyzer or universal testing machine.
• Environmental chamber or controlled humidity box.
• Analytical balance.
• Digital caliper with data output.
• Drying oven or dehydrator.
• Incubator or temperature-controlled growth space.
• Scanning electron microscope for surface structure analysis.
• FTIR or other spectroscopy tool for compositional comparison.
• Image analysis setup for pore size and surface coverage.
• Sterile transfer tools and laminar flow access for cleaner inoculation.
• Data logging hygrometer and temperature sensors.
• Reference packaging foam samples for benchmarking.

Software & Tools

• Google Sheets: Organizes measurements, graphs density and strength, and helps you compare growth groups.
• Python: Fits regression or machine learning models that connect growth conditions to material outcomes.
• ImageJ: Measures sample area, surface coverage, and visible pore structure from photos.
• Orange Data Mining: Builds simple predictive models without much coding.
• Jamovi: Runs basic statistics and group comparisons with a clear interface.

Experiment Steps

1. Define one main question and choose the growth variable you will change first.
2. Set up a small set of sample groups so you can compare the effect of each condition.
3. Decide how you will measure density, compressive strength, and biodegradation in a repeatable way.
4. Build a standard reference so your measurements can be compared across batches.
5. Plan controls that separate fungal growth effects from moisture, shape, and drying effects.
6. Choose a modeling approach that matches your data size, then test whether it predicts outcomes on new samples.

Common Pitfalls

• Using coffee grounds that are still wet, which adds extra water and changes growth speed and final density.
• Letting sample shapes vary from mold to mold, which makes strength comparisons unfair.
• Measuring compressive strength before samples reach the same dryness level, which skews the results.
• Growing samples in uneven humidity, which creates different skin thickness and pore structure across the batch.
• Testing biodegradation without tracking moisture and mass loss separately, which can mix up swelling, drying, and true decay.

What Makes This Competitive

A strong version of this project does more than compare a few homemade samples. You can improve it by using tight controls, enough repeats, and a clear model that predicts material performance from growth conditions. You can also compare your biocomposite against a commercial foam sample, then use statistics to test whether the difference matters. If you add image analysis or a simple machine learning model, your project starts to look like real materials research.

Project Variations

• Test whether different waste feedstocks, like tea leaves or sawdust, change strength more than coffee grounds do.
• Compare oyster mushroom growth on open-air molds versus sealed molds to see how oxygen exposure changes the final foam.
• Measure how surface texture or pore size relates to compressive strength, then use image analysis to predict failure points.

Learn More

• PubMed: Search for review articles on mycelium-based composites, packaging materials, and fungal biopolymers.
• USDA National Agricultural Library: Search for resources on agricultural waste feedstocks and biomass-based materials.
• NIH PubChem: Look up the chemical components of coffee grounds and common substrate additives.
• MIT OpenCourseWare: Find free materials science and engineering lecture notes that cover stress, strain, and material testing.
• NOAA National Centers for Environmental Information: Use climate and humidity background data to understand how moisture affects materials.