Dynamic Behavior of Vertically Aligned Carbon Nanotube Foams with Patterned Microstructure

We present the design, fabrication, and dynamic characterization of micropatterned vertically aligned carbon nanotube (VACNT) foams. The foams' synthesis combines photolithographic techniques with chemical vapor deposition to create materials with an effective density up to five times lower than that of bulk VACNT foams. The dynamic response of these lightweight materials is characterized by performing impact tests at different strain rates. Results show that the dynamic stress-strain behavior of the micropatterned foams is governed by the patterns' geometry and has negligible dependence on their bulk density. The energy absorption of the micropatterned foams is higher than most other energy absorbing materials, such as honeycombs, foams, and composites of comparable density. Highly organized CNT microstructures can be employed as lightweight material for protective applications.