Two-layer plate mechanical metamaterials

Abstract

We present the fabrication and characterization of plates made from two ultrathin layers and capable of withstanding repeated extreme mechanical deformation. The ultrathin layers, one flat and the other corrugated, are less than 100 nm thick and created using atomic layer deposition, forming a joined structure similar to conventional honeycomb sandwich plates. The structures exhibit a high bending stiffness while still possessing a low area density of approximately 0.5 g/m2. Finite element simulations show that the bending stiffness initially increases quadratically with the height of the plate, but saturates at very large heights. Measurements of bending stiffness using an atomic force microscope agree qualitatively with the simulations.