Munjoi - Algae-Based Biodegradable Footwear — Munjoi

Biological model: Algal cell walls and biopolymers

Company: Munjoi

Algae's structural biopolymers inspire foam materials for fully biodegradable, multifunctional footwear, replacing petroleum-based polymers.

The challenge

Footwear industry produces ~3 billion pairs annually, 80% using petroleum-based foams (EVA, polyurethane) that persist for 40+ years in landfills. Conventional shoes accumulate in waste streams, degrading into microplastics. Biodegradable alternatives are needed.

Nature's strategy

Algae synthesise strong, water-resistant cell wall polysaccharides that are fully biodegradable and decompose rapidly when exposed to soil microorganisms.

What was emulated

Biopolymer structure; lightweight foam architecture; water resistance without polymeric films; complete biodegradability; photosynthetic feedstock.

The innovation

Algae-derived polysaccharide foam materials that provide equivalent cushioning and durability to petroleum-based foams whilst remaining fully compostable.

Full case study

Algae synthesise strong, lightweight cell walls from polysaccharides (cellulose, alginates, agar) that provide structural support whilst remaining fully compatible with microbial decomposition—a feat petroleum-based foams cannot match. When algae die, these polymers are rapidly consumed by soil microorganisms, cycling back into ecosystem productivity. Munjoi recognised that algal polysaccharides could be extracted, processed, and formed into foam materials providing cushioning, insulation, and water-resistance equivalent to petroleum-based EVA and polyurethane foams, yet fully biodegradable. The company cultivates algae (specifically fast-growing Chlorella and Spirulina), extracts polysaccharide fractions, and converts them into closed-cell foam through fermentation and controlled gelatinisation. Munjoi shoes feature algae-foam soles, linings, and structural elements, combined with organic cotton uppers. Field testing shows comfort and durability matching conventional shoes through 12+ months of wear, at which point the entire shoe is compostable. By replacing petroleum with photosynthetic algae, Munjoi achieves a truly circular footwear system: CO2 capture during algae growth, end-of-life compostability, and zero synthetic residues.