Catastrophic collapse of materials and structures is the inevitable consequence of a chain reaction of locally confined damage—from solid ceramics that snap after the development of a small crack to metal space trusses that give way after the warping of a single strut.
In a study published this week in Advanced Materials, engineers at the University of California, Irvine and the Georgia Institute of Technology describe the creation of a new class of mechanical metamaterials that delocalize deformations to prevent failure. They did so by turning to tensegrity, a century-old design principle in which isolated rigid bars are integrated into a flexible mesh of tethers to produce very lightweight, self-tensioning truss structures.
Starting with 950 nanometer-diameter members, the team used a sophisticated direct laser writing technique to generate elementary cells sized between 10 and 20 microns. These were built up into eight-unit supercells that could be assembled with others to make a continuous structure. The researchers then conducted computational modeling and laboratory experiments and observed that the constructs exhibited uniquely homogenous deformation behavior free from localized overstress or underuse.
