Spatiotemporal control over DHF thermosets. Credit: Nature (2025). DOI: 10.1038/s41586-024-08386-w Car tires, replacement hip joints, bowling balls—these and other items are made from a class of plastics called thermosets, known for extreme durability. Their "crosslinked polymer" chemical structure guarantees longevity but also makes these petrochemical-based materials—which comprise 15%–20% of all polymers produced—impossible to recycle. "Currently, zero percent of the world's thermoset materia...