Researchers at Harvard’s Wyss Institute may have come up with a solution to the environmental impacts of plastic waste. By isolating chitin, a material found in shrimp shells and the second most abundant organic material found on earth, the team have engineered a bioplastic suitable for use in traditional plastic shaping techniques. This new material, called “shrilk,” is both suitable for use in mass production and capable of fully biodegrading, something that bioplastics have fallen short of until now. From Harvard Gazette:
Chitin, a tough polysaccharide, is the main ingredient in the hardy shells of crustaceans, the armorlike cuticles of insects, and even the flexible wings of butterflies.
The Wyss Institute makes its shrilk from chitin from shrimp shells, most which would otherwise be discarded or used in fertilizer or makeup, and a fibroin protein from silk. Researchers discussed it in a March online study in the journal Macromolecular Materials & Engineering.
Shrilk is cheaply and easily fabricated by a novel method that preserves chitosan’s strong mechanical properties. The researchers said that for the first time, this tough, transparent, and renewable material can be used to make large, 3-D objects with complex shapes using traditional casting or injection-molding techniques. That means objects made from shrilk can be mass-manufactured and will be as robust as items made with the everyday plastics used in toys and cell phones.
“There is an urgent need in many industries for sustainable materials that can be mass produced,” Wyss Director Donald E. Ingber said in March. “Our scalable manufacturing method shows that chitosan, which is readily available and inexpensive, can serve as a viable bioplastic that could potentially be used instead of conventional plastics for numerous industrial applications.”
This environmentally safe alternative to plastic could also be used to make trash bags, packaging, and diapers.
Once discarded, shrilk breaks down in just a few weeks — and even releases rich nutrients that support plant growth. In one experiment, Wyss Institute researchers grew a California black-eyed pea plant in soil enriched with its chitosan bioplastic. Within three weeks, the material encouraged plant growth.