Scientists mimic seashells to improve recycled plastic performance

Researchers at Georgia Tech, led by aerospace engineering assistant professor Christos Athanasiou, have developed a bio-inspired material that mimics the structure of seashells to improve the performance and consistency of recycled plastics. By replicating nacre—the natural architecture of seashells composed of brittle mineral “bricks” bonded with soft protein “mortar”—the team created a composite using recycled high-density polyethylene (HDPE) sheets layered with a softer adhesive polymer. This design significantly reduces variability in mechanical properties, maintaining the strength of virgin plastics while improving reliability, particularly in maximum elongation by over 68%. This advancement addresses a major challenge in recycling, where less than 10% of plastics are effectively reused due to inconsistent material quality. The seashell-inspired approach restores trustworthiness in recycled HDPE, which typically degrades after exposure to sunlight and heat, limiting its reuse in high-performance applications. The researchers also introduced an “uncertainty-aware” Tension Shear Chain model to quantify both