In-situ Investigation of Energy Dissipation Mechanisms in CNT-based Foams

In an effort to characterize superior mechanical energy absorption properties of carbon nanotube (CNT)-based foams, we present results of uniaxial compression experiments of free-standing CNT foam ¿pillars¿. These cylinders are created by focused ion beam (FIB) with enhanced carbon etch chemistries and are subsequently compressed using a one-of-a-kind in-situ micro-mechanical instrument comprised of SEM and Nanoindenter, SEMentor. The experiments span 4 orders of magnitude in strain rate and show that these foams are nearly 100' compressible, with the amount of absorbed energy varying with strain rate and peak stress. These concepts are discussed in the context of energy absorption diagrams and governing deformation mechanisms prevalent in these multi-scale structures.

Date/Time: 
05/03/2009 - 17:00