A film of PLA (polylactic acid) plastic immediately after being placed in compost (left) and after one week in the compost (right). Embedded with an enzyme, the PLA plastic can biodegrade to simple molecules, making it promising as a future alternative to a non-degradable plastic. (Image: Adam Lau/Berkeley Engineering)

If only there were some kind of plastic-eating creature that roamed the world devouring our water bottles, food containers, cling film, grocery bags, straws, caps, broken toys, etc., the plastic waste problem filling our landfills, polluting our waterways, and floating through our very bloodstreams, might go away.

No one has created such a beast, sadly, but, thanks to the work of a small handful of researchers out of UC Berkeley, tomorrow’s plastics may be able to eat themselves. The team found a way to embed plastic-munching enzymes into plastics so that, with water and heat, they would break down completely, with not a trace of plastic left behind.

Polymer-breaking enzymes aren’t new — our bodies break down proteins and starches, both of which are polymers, every day. But a polymer-snipping enzyme placed atop a plastic degrades it more or less haphazardly, leaving plastic bits and pieces of various sizes unconsumed.

“That’s how you end up with microplastics,” said Aaron Hall, Founder and CEO of Intropic Materials and one of the former UC Berkeley researchers. “In our work, an enzyme grabs one end of a chain and starts pulling it through and cutting it, one by one. Then it will grab the next one and pull it through — in the end it’s completely cut up and in a systematic way.”

The effectiveness of the enzyme to reduce plastic to its origins means not much of it is needed in a plastic to make that plastic compostable — something between 0.02 and 1.5 percent. To enable the processing of their enzymes into plastics, they are coated with a water-soluble polymer that acts like PPE for the enzyme. These protected enzymes only activate when the plastic is submerged in water and hotter than 104 °F. The success of the concept won the UC Berkeley team SAE’s Create the Future Design Contest award in 2021.

After earning his PhD, Hall decided to turn the idea into a commercial product. “I did some soul searching,” he said. “I decided the world wants this and needs this and this is what I should be spending my time doing. I decided to take the plunge, and I’ve been at it ever since.” So, he started Intropic Materials.

Since winning the award from SAE, Hall has been busy establishing his business. Thanks to a fellowship from Activate Cyclotron Road, the company has been able to create its own lab at Lawrence Berkeley National laboratory. And they’ve hired a chemical engineer, Jolene Mattson, with extensive experience in process engineering to help ramp up from proof-of-concept basic research to commercial product.

At UC Berkeley, Hall and his colleagues used two naturally occurring enzymes. Now they’re exploring a range of natural and synthetic enzymes which may allow them to expand this self-destructing plastic idea to a wider array of plastics. They are also exploring which applications and environments are most appropriate for the use of these materials since water and heat together activate the plastics. “Thinking ahead, there are certainly opportunities to engineer and do clever tricks to adjust and account for those types of changes,” said Hall. “That’s coming down the pipeline.”

But long before that kind of finessing takes place, Hall and his researchers at Intropic Materials must figure out the best way to begin manufacturing their product in quantity. “We’re focusing on scaling up from grams to kilograms to tons and beyond so we can actually start getting these enzymes into the materials,” said Hall. “Plastic is this amazing material, but such a problem. We can do better.”

Michael Abrams is a science and engineering writer based in New Jersey.

Aaron Hall