Ultralight shape-recovering plate mechanical ALD metamaterials

Here is an Ultracool ALD application for creating Ultralight shape-recovering plate mechanical  metamaterials from University of Pennsylvania. Check out the paper and the Youtube video below. 

Sequential images of a structure with the ALD layer thickness of ~25 nm inside an FIB while being manipulated using a micromanipulator. (Nature Communications 6, Article number:10019 doi:10.1038/ncomms1001)

All details on the fabrication method can be found in the supplementary information document with free access: http://www.nature.com/ncomms/2015/151203/ncomms10019/extref/ncomms10019-s1.pdf

And the paper itself is OPEN ACCESS !

Fabrication method of the periodic three-dimensional architecture of the mechanical metamaterial as described in the supplementary information document (Nature Communications 6, Article number:10019 doi:10.1038/ncomms1001)

Ultralight shape-recovering plate mechanical metamaterials

Keivan Davami, Lin Zhao, Eric Lu, John Cortes, Chen Lin, Drew E. Lilley, Prashant K. Purohit & Igor Bargatin

Nature Communications 6, Article number:10019 doi:10.1038/ncomms10019 Published 03 December 2015 

Unusual mechanical properties of mechanical metamaterials are determined by their carefully designed and tightly controlled geometry at the macro- or nanoscale. We introduce a class of nanoscale mechanical metamaterials created by forming continuous corrugated plates out of ultrathin films. Using a periodic three-dimensional architecture characteristic of mechanical metamaterials, we fabricate free-standing plates up to 2 cm in size out of aluminium oxide films as thin as 25 nm. The plates are formed by atomic layer deposition of ultrathin alumina films on a lithographically patterned silicon wafer, followed by complete removal of the silicon substrate. Unlike unpatterned ultrathin films, which tend to warp or even roll up because of residual stress gradients, our plate metamaterials can be engineered to be extremely flat. They weigh as little as 0.1 g cm⁻² and have the ability to ‘pop-back’ to their original shape without damage even after undergoing multiple sharp bends of more than 90°.