A bioplastic version of expanded polystyrene (EPS) was created by design duo Charlotte Böhning and Mary Lempres in the United States. The solution is made from the exoskeleton of the larva of Tenebrio molitor better known as the mealworm.
The insect is already used in the production of animal feed and, in 2021, was approved in the European Union as human food. Now applying it to the development of the new material means the plastic can decompose in the ground within weeks.
Called chitofoam, the “polystyrene foam” compostable is waterproof and can be molded into different shapes and packages. For example, its use in the manufacture of glasses or imitating polystyrene foam to package fragile products.
Unlike polystyrene, which is petroleum-based, chitofoam is derived from a biopolymer called chitin. In nature, chitin is the second most abundant organic polymer after cellulose. The larvae use this substance to build their strong and flexible exoskeleton.
“We are pushing our solution even further, reinventing packaging and designing more efficient and structured ways to preserve and protect products,” explain the creators.
The development of the new material is based on research from Stanford University in 2015, which identified the great potential of mealworms to biodegrade expanded polystyrene. It turned out that 100 larvae could eat 40 milligrams of styrofoam a day without affecting their health or “edibility”.
Creating a more environmentally friendly substitute for regular polystyrene foam would reduce the pollution of polystyrene foam and its low recycling rate. Styrofoam does not biodegrade and simply fractures into smaller and smaller pieces called “microplastics”.
When developing the project, the designers realized that Americans alone throw away about 25 billion polystyrene cups a year. If each glass can take up to half a millennium to degrade, imagine the long-term environmental impact.
Another problem they highlight is that polystyrene recycling is possible, but rarely practiced because the process is expensive, difficult and without a real market.
Chitofoam compostable polystyrene foam is one of the finalists of the 2022 Lexus Design Award an award focused on design and innovation.