Researchers at the Lawrence Livermore National Laboratory and the Massachusetts Institute of Technology have developed a material that can withstand a load of at least 160,000 times its own weight, according to a June 20 article in the journal Science on June 20.
The material, created by using additive micro-manufacturing processes, could have a significant impact on industries where lightweight, high-stiffness, and high-strength materials are used. Demand for lightweight materials from the automotive industry has been particularly high.
The material is so light that it’s been called “frozen smoke.”
The researchers developed micro-architected meta-materials — artificial materials with properties not found in nature — that maintain a nearly constant stiffness per unit mass density, even at ultra-low density.
Most lightweight cellular materials have mechanical properties that degrade substantially with reduced density because their structural elements are more likely to bend under applied load. However, the team’s meta-materials exhibited ultra-stiff properties across more than three orders of magnitude in density.
According to LLNL engineer Xiaoyu “Rayne” Zheng, lead author of the Science article, the key to the ultrahigh stiffness is that all the micro-structural elements in the material are designed to be over constrained and do not bend under applied load.
The team observed the high stiffness with constituent materials such as polymers, metals and ceramics.
LLNL engineer Chris Spadaccini noted that the micro-architected materials have properties that are governed by their geometric layout at the microscale, as opposed to chemical composition. The materials were fabricated using projection micro-stereolithography.
The additive micro-manufacturing process involves using a micro-mirror display chip to create high-fidelity 3D parts, one layer at a time, from photosensitive feedstock materials.
It is now possible to print a stiff and resilient material using a desktop machine, MIT professor Nicholas Fang saud. This will make it possible to rapidly make many sample pieces and see how they behave mechanically.
The team’s new materials are 100 times stiffer than other ultra-lightweight lattice materials previously reported in academic journals.
Photo Credit: Julie Russell/LLNL