Ultra‐Light and Scalable Composite Lattice Materials

Architected lattice materials are some of the stiffest and strongest materials at ultra‐light density (<10 mg cm^?3), but scalable manufacturing with high‐performance constituent materials remains a challenge that limits their widespread adoption in load‐bearing applications. We show mesoscale, ultra‐light (5.8 mg cm^?3) fiber‐reinforced polymer composite lattice structures that are reversibly assembled from building blocks manufactured with a best‐practice high‐precision, high‐repeatability, and high‐throughput process: injection molding. Chopped glass fiber‐reinforced polymer (polyetherimide) lattice materials produced with this method display absolute stiffness (8.41 MPa) and strength (19 kPa) typically associated with metallic hollow strut microlattices at similar mass density. Additional benefits such as strain recovery, discrete damage repair with recovery of original stiffness and strength, and ease of modeling are demonstrated.