If you stand on a beach in India or Thailand, you’ll likely see dozens of flip-flops wash up onto the shore. An estimated three billion end up in waterways or the ocean every single year, choking sea life and breaking into tiny particles that end up in the food chain.
But a small lab in San Diego called Algenesis has found a solution to the world’s flip-flop problem. It’s developed a biodegradable, algae-based polyurethane, the foamy plastic that’s commonly used to make the footbeds of shoes and sandals. Next year, it will launch a flip-flop brand in-house to demonstrate this material in action. This plastic has the potential to transform not only the $215 billion footwear industry but also the $1.2 trillion plastic industry, which churns out more than 300 tons of plastic every year.
So what makes this material so much better than traditional plastic? For one thing, it requires a lot less carbon to manufacture. Traditional plastic is made from crude oil, a resource that comes from ancient algae (among other plants) that are baked under the earth’s surface for millions of years at high pressure. Extracting oil, then refining it, is a highly carbon-intensive process that accelerates climate change. Algenesis, meanwhile, transforms algae directly into oil, then into plastic, in a controlled lab setting. “You extract the oil from algae in similar ways that you extract oil from soybeans or canola seeds,” says Stephen Mayfield, director of the California Center for Algae Biotechnology at U.C. San Diego, who founded Algenesis five years ago. “Once we get the oil, we chemically process it to form polyurethanes.”