Flip-flops, the footwear that can either feel comfortable of feel like a knife is being inserted in-between your toes, are having a moment during this unusual lockdown summer and are seeing a surge in sales in the UK. Yet, have you ever thought about them being biodegradable?
Well, researchers at University of California (UC) San Diego have devised a new way for sun seekers to care for the environment when they hit the beach — biodegradable flip-flops made from algae.
Teaming up with La Jolla start-up company Algenesis Materials, scientists have spent years working to produce a solid foam-like material out of oil extracted from algae to make the green beach sandals.
The team succeeded in formulating polyurethane foams made from algae oil to meet commercial specifications for the foot-bed of flip-flops. The results of their work are published in Bioresource Technology Reports and describe the team’s successful development of these sustainable, consumer-ready and biodegradable materials.
UC San Diego (@UCSanDiego) Biological Sciences Professor Stephen Mayfield said: “Working with our commercial partner Algenesis, using commercial-quality, biodegradable foams (made from algal biomass), we made viable shoes and degraded them, characterising everything that came off of them as they degraded—including the organisms that ate them. We realised we could use those by-products to synthesise more polyurethanes to create a ‘bioloop.’”
“After hundreds of formulations, we finally achieved one that met commercial specifications. These foams are 52% biocontent—eventually we’ll get to 100%.”
Mayfield and his team hope the sustainable footwear, which is due to be launched through a major flip-flop brand next year, will cut the amount of plastic ending up in oceans and landfill sites.
“There are over one billion flip-flops made in the world every year and are actually a major plastic pollution in the oceans,” said Mayfield.
Mayfield, director at the California Center for Algae Biotechnology, and associate director Michael Burkart co-led the project with graduate student Natasha Gunawan and Marissa Tessman, a research scientist at Algenesis Materials (@Algenesis_) .
Searches for flip-flops have increased 53% since June, according to online fashion search business Lyst, with demand for Havaianas up 89% month-on-month. And while flat sandals in general are proving popular, “flip-flops in particular have seen something of a resurgence as an alternative to the classic Birkenstock”, according to Selfridges accessories and shoes buying manager, Josie Gardner.
Flip-flops are usually made from fossil fuel-based plastics. However, more and more consumers are looking for alternative materials.
“Public sentiment is coming around and people are demanding a turn toward sustainable products,” said Burkart. “We are lucky to be at the right place at the right time.”