Final Report: Growth of a Fungal Biopolymer to Displace Common Synthetic Polymers and Exotic Woods
EPA Contract Number:
Growth of a Fungal Biopolymer to Displace Common Synthetic Polymers and Exotic Woods
Ecovative Design, LLC
Manager, SBIR Program
May 15, 2013 through
November 14, 2013
Small Business Innovation Research (SBIR) - Phase I (2013)
Small Business Innovation Research (SBIR)
SBIR - Innovation in Manufacturing
Ecovative is developing a revolutionary new sustainable material that harnesses fungi’s tendency to grow into and fill void space under certain environmental conditions. This groundbreaking technology allows for a biopolymer composed of a tightly woven network of mycelia to be grown into any desired shape. This sustainable mycelium-based biopolymer is fully compostable at the end of its useful life, making it an attractive environmentally friendly alternative to its synthetic counterparts, which use fossil fuel feed stocks and are non-compostable.
Ecovative has been developing this potential ethylene-vinyl acetate (EVA)-replacement technology with feedback from the world’s leaders in shoe manufacturing. These companies support the further development of this technology to replace the EVA foam used in mid-sole shoe soles. This is the primary market segment where current efforts at Ecovative are being directed, as there are relatively few alternatives to EVA for producing athletic footwear midsoles.
The ability to grow material that is consistent throughout the entirety of the specimen is the most crucial characteristic to break into any material market. The time to fill, or grow into, a designated volume should be minimized, as this will cut production cost dramatically. The materials strength performance characteristics, specifically tensile strength and compression/rebound, are important to meeting the metrics set forth by shoe manufacturing companies. A variety of incubation parameters (carbon dioxide concentrations, temperatures, gravitational force) were evaluated by these metrics for their effect of biopolymer growth. The results of these tests, coupled with research that Ecovative has accomplished outside of the scope of this contract, will inform the second phase of development required to commercialize fungal biopolymers as a mid-shoe sole replacement.
According to an industry report compiled by Foresight Science and Technology, the global athletic footwear market, the end use market where this athletic shoe midsole application resides, is expected to reach $195 billion by 2015.1 Presently, EVA dominates this market, and a natural alternative does not exist for regional distribution. The demand for all forms of EVA globally is expected to grow at a compound annual growth rate of 5.6 percent through 2016, from base demand of 2.7 million tons in 2009.”1 The cost of EVA ranges between $0.50 and $1.00/lb, making this a 1.35 to 2.7 million dollar market annually. The athletic footwear industry is an ideal market entry point for the fungal biopolymer technology as this is a rapidly renewable product, and the industry has resolved to increase the sustainability of their products with limited options for alternative materials.
The first part of the study was to determine which series of environmental conditions allowed for the optimal growth of the biopolymer material. The substrata were composed of ratios of kenaf pith, nutritive supplements, trace carbohydrates and mineral salts. The optimal conditions were quantified based on tested metrics: tensile strength (ASTM D-638), compressive strength (ASTM C-165), as well as material homogeneity based on observation. Results determined that hyphal, or individual tissue fiber, alignment has a great effect on the strength characteristics of the resulting material. Horizontally grown material, conferring a high degree of directional growth and hyphal alignment produced material with high tensile strength. Material that was grown vertically, an un-oriented morphology, resulted in a higher density and compressive strength. Environmental conditions allowing for the consistent production of biopolymer into a void space and resulted in the highest tensile and compressive strength will be pursued for scale up.
The second part of the work plan examined compression as a post-processing step: no compression; 2x compression (two specimens compressed to the initial volume of one, thus doubling the density); and 3x compression (three specimens compressed to the initial volume of one). Compression tools were constructed at Ecovative that used a porous membrane and allowed for the additional growth of the material during compression. The resultant strength metrics generally showed that the 3x compression sets had a significantly higher strength to density ratio than non-compressed material, proving that mycelial growth under compression bolsters the strength of the material.
The last examination was the addition of morphological modifiers to the mycological composites during growth under ideal environmental conditions. The addition of compounds to induce the formation of branching hyphae throughout the composite were tested and compared to the controls of the biopolymer incubated under the same conditions, as well as to EVA. No morphological modifiers exhibited any significant increase in strength.
Several tests were conducted on the fungal biopolymer specimens outside of the scope of the contract and included many avenues for scaled production of the biopolymer as well as drying procedures. Large volumes of biopolymers can be produced through many different methods. Large sheets can be grown that can undergo a variety of post-processing procedures to produce EVA-like materials. Six different fungal species were trialed during the course of this study, proving that the strain used was the most prolific at producing biopolymer. Fungal biopolymers also exhibit different strength and physical characteristics after they have undergone different drying regimes. The preservation of the mycelial cellular structure proves the most crucial for future development toward an EVA-replacement.
Scaling this technology to further accommodate larger materials, such as large sheets of biopolymer, would start in mid-2015 under an SBIR Phase II demonstration. Ecovative has the capacity to produce approximately 250,000 cubic feet of this biopolymer annually using its existing facilities. The anticipated launch for fungal biopolymer is in early 2016, after the final compliance tests and customer metrics are met.
 Turnblom, E. Wayne. Commercialization Assessment Report: Mycelium-based Biopolymers. EPA0698TN. Providence: Foresight Science & Technology, 2013. Report.
bio-plastic, mycological polymers, renewable
SBIR Phase II:
Mycological Biopolymer as a Replacement for Expanded Plastic Foams