Ultralight Metallic Microlattices

1. T. A. Schaedler¹,*, 
2. A. J. Jacobsen¹, 
3. A. Torrents², 
4. A. E. Sorensen¹, 
5. J. Lian³, 
6. J. R. Greer³, 
7. L. Valdevit²,
8. W. B. Carter¹

1. Science 18 November 2011: 
   Vol. 334 no. 6058 pp. 962-965 
   DOI: 10.1126/science.1211649

ABSTRACT

Ultralight (<10 milligrams per cubic centimeter) cellular materials are desirable for thermal insulation; battery electrodes; catalyst supports; and acoustic, vibration, or shock energy damping. We present ultralight materials based on periodic hollow-tube microlattices. These materials are fabricated by starting with a template formed by self-propagating photopolymer waveguide prototyping, coating the template by electroless nickel plating, and subsequently etching away the template. The resulting metallic microlattices exhibit densities ρ ≥ 0.9 milligram per cubic centimeter, complete recovery after compression exceeding 50% strain, and energy absorption similar to elastomers. Young’s modulus Escales with density as E ~ ρ², in contrast to the E ~ ρ³ scaling observed for ultralight aerogels and carbon nanotube foams with stochastic architecture. We attribute these properties to structural hierarchy at the nanometer, micrometer, and millimeter scales.