Composites · Sustainability · Compositive

Mycelium Helmet

A bicycle helmet made from mycelium (mushroom) composite — grown, not manufactured.

Overview

Compositive was founded on a straightforward premise: helmets don't need to be made from foam and plastic. Mycelium — the root structure of fungi — can be grown into any shape, is fully compostable, and has excellent impact-absorption properties. We set out to prove it could replace EPS in a bicycle helmet.

Personally led the engineering team, defined the helmet geometry and structural requirements, and developed the production process from scratch. This was a genuinely novel materials application with no established playbook to follow.

Engineering scope

Helmet form design — balancing ventilation, coverage, aesthetics, and mould geometry
Structural analysis of mycelium composite properties under impact loading
Growth process development: substrate formulation, mould design, curing conditions
Production plan and scale-up pathway
Financial modelling and venture case for investor presentations

Process & prototyping

Helmet moulds for growing the mycelium form — Moulds that shape the helmet as the mycelium grows. Personally designed the helmet, CNC'd positive forms, vacuum formed the moulds. I then resin 3D printed the adjustable internal negatives, using magnets as fastening mechanisms

Laminar flow hood used for sterile mycelium cultivation — Personally designed and built a Flow hood for sterile substrate preparation and inoculation.

Outcome

Functional prototypes produced and tested. Financial case built and presented. The venture demonstrated the viability of mycelium as a structural composite material for wearable applications.