Students, researchers turn algae into renewable flip-flops

A team of researchers and students at the University of California, San Diego are trying to curb the number of petroleum-based flip flops — currently, 3 billion every year — that end up in landfills.


Their solution is the world’s first algae-based, eco-friendly pair of flip flops.

“Even though a flip flop seems like a minor product, a throwaway that everyone wears, it turns out that this is the number one shoe in the world,” Stephen Mayfield, a professor of biology at UCSD, said in a news release.

In India, China and Africa, the flip flop is the most popular shoe.

“These are the shoes of a fisherman and a farmer,” Mayfield said.

Flip flops are responsible for a large amount of the polyurethane that ends up in the ocean. But researchers originally set their sights on the pollution caused by surfboards.

Two years ago, Mayfield and Skip Pomeroy, a professor of chemistry and biochemistry, worked with their students to design an algae-based, biodegradable surfboard. They teamed up with a local surfboard blanks manufacturer, Arctic Foam of Oceanside, to produce the board.

Soon, Mayfield and Pomeroy realized their technology could be used to replace other petroleum-based, polyurethane products.

“The algae surfboard was the first obvious product to make, but when you really look at the numbers you realize that making a flip-flop or shoe sole like this is much more important,” says Mayfield. “Depending on how you do the chemistry, you can make hard foams or soft foams from algae oil. You can make algae-based, renewable surfboards, flip-flops, polyurethane athletic shoes, car seats or even tires for your car.”

Petroleum is formed by ancient plant material like algae, but the chemical potential for petroleum is present in living algae. By converting living algae into petroleum and then into polyurethane, researchers are pulling carbon from the atmosphere instead of taking it out of reserves in the ground. This is what makes their algae-based polyurethane more sustainable.

Researchers are also working to make the carbon bonds in their polyurethane more biodegradable, so that microorganisms can more easily break them down.

In an effort to take their research to market, researchers have spun their work off into a new company called Algenesis Materials. Their first product is the Triton flip flop. The researchers hope to continue perfecting the chemistry behind the Triton flip flop and use it to make more eco-friendly shoe soles, car seats and more.

“The idea we’re pursuing is to make these flip-flops in a way that they can be thrown into a compost pile and they will be eaten by microorganisms,” said Mayfield.

Algae-based surfboards have already become popular in the surfing industry, and researchers hope their latest efforts will have a similar impact on the shoe industry.

“It’s going to be a little while before you can buy one of these flip-flops in the store, but not too long,” says Mayfield. “Our plan is that in the next year, you’ll be able to go into the store and buy an Algenesis flip-flop that is sustainable, biodegradable and that was invented by students at UC San Diego.”

By Brooks Hays