A blade spinning on a lab bench is woven from bamboo and grown fungus, and engineers say roughly 95 percent of it can be composted

A woven blade about two feet long sits on a bench in an engineering lab at UC Davis.

It looks almost nothing like a turbine blade.

Run a finger along it and you feel plant fiber, not fiberglass.

Inside the woven shell is something stranger still, blocks of fungal mycelium that were grown rather than molded.

A team there has spent years coaxing this combination into the shape of a working wind blade.

So can mushrooms and bamboo really do the job fiberglass and balsa do now?

What is actually holding this blade together?

The shell starts with bamboo reeds, woven by hand the way a basket is woven, standing in for the fiberglass skin of a conventional blade. Inside it sit blocks of mycelium grown on biomass from agricultural waste, taking the place of the balsa wood core.

The fungus is not decoration. It is structural filler that is grown to shape instead of milled.

Because bamboo is naturally antifungal, mycelium will not readily take to it, so the group had to work out an interface between the two and a glue that would not spoil the compost pile at the end. They settled on pine resin glue, and the grown blocks are dried to halt the fungus without ruining its stiffness.

Plywood ribs and a 3D printed connector between rotor and blade are the main exceptions to the record breaking, self leveling recipe of plant fiber and fungus. Valeria La Saponara, the polymer composites professor in the Department of Mechanical and Aerospace Engineering who leads the work, has put the finished blade at roughly 95 percent biodegradable by surface and by weight. That is the whole point of the swap, since the hardest part of a conventional blade to undo is the bond itself.

What does the test setup actually look like?

The hardware lives away from central campus, near the STEEL Lab at the Western Cooling Efficiency Center. The turbines themselves are ordinary small commercial machines bought off the shelf, and the plan is to pull the manufacturer’s blades and bolt the compostable ones on in their place.

The first woven blade was about two feet long, built for a 400 watt turbine purely as proof that the weave could hold an airfoil shape. By La Saponara’s own account that one was never put through a rotation test and is kept for demonstrations.

The second generation is bigger, built for a 1 kilowatt turbine, with blades roughly a yard long. That is the size La Saponara has called a reasonable amount of power, the point at which she has said the team could start talking to companies about distributed energy uses.

How hard are they planning to push it?

The number the team has aimed at is 800 RPM, which is the nominal speed of the commercial 1 kilowatt turbine. The first data point they wanted from a dynamometer run was simply the speed the blade survives without shattering.

That is a little over 13 full rotations every second, and La Saponara has been candid that the team did not know whether a woven blade would reach it.

Spin alone does not capture what a turbine meets outdoors, so a second target sits alongside it, resilience in winds of up to 85 miles an hour, gusts strong enough to snap limbs and strip shingles. The college has posted video of a rotation test carried out this past spring, but the lab has not published results from it, so the honest status of both numbers is goal, not achievement.

Why bother replacing balsa and fiberglass at all?

The forest connection is part of the motivation. Most of the world’s balsa comes from Ecuador, and while it was historically grown on plantations, a surge in demand around 2020 outstripped that supply and pulled illegal logging into natural forest. Agriculture, not wind, remains the main driver of Amazon deforestation.

The end of a blade’s life is the clearer problem. Fiberglass and cured resin are nearly impossible to separate, which is why worn out blades are often sawn into sections and buried, the same dead end driving separate work on solar hardware such as the laser recovery process being tested on retired panels.

A blade that starts as plant fiber and fungus is designed to avoid that fate. It gets shredded and composted rather than trucked to a landfill cell, a destination already familiar to broken turbine blades elsewhere.

So is this actually going to show up on a wind farm?

Not soon. A 1 kilowatt machine is backyard scale, nowhere near the multi axle turbines turning over American farmland, and scaling a woven bamboo shell to a blade seventy or a hundred feet long is an open engineering question.

Even so, the stated next step is more modest: proof of concept at 1 kilowatt, then a push toward 10 kilowatts, a size that could matter for remote cabins, small farms or disaster relief.

La Saponara has framed the goal in plain terms, saying the team wants “to be good citizens for everybody,” which in practice means clean power that does not leave a hidden waste cost behind it.