Architected carbon nanotube foams and methods of making same

A helmet comprising a foam comprising tubes substantially aligned longitudinally in a first direction, wherein:

• each tube defines an outer wall and an inner wall, and each tube comprises an entangled bundle of carbon nanotubes substantially aligned longitudinally in the first direction;
• and
• tubes in at least a subset of the tubes are positioned with respect to each other to form one or more first hexagonal units, wherein each first hexagonal unit comprises first-hexagonal-unit tubes, wherein the first-hexagonal-unit tubes comprise six peripheral first-hexagonal-unit tubes and a central first-hexagonal-unit tube, wherein the six peripheral first-hexagonal-unit tubes surround the central first-hexagonal-unit tube in a juxtaposed, hexagonal configuration, and further wherein:
• the helmet is configured to cover at least a portion of an object and to attenuate an external force acting on the object.

A foam comprising tubes substantially aligned longitudinally in a first direction, wherein:

• each tube defines an outer wall and an inner wall, and each tube comprises an entangled bundle of carbon nanotubes substantially aligned longitudinally in the first direction;
• and
• tubes in at least a subset of the tubes are positioned with respect to each other to form one or more first hexagonal units, wherein each first hexagonal unit comprises first-hexagonal-unit tubes, wherein the first-hexagonal-unit tubes comprise six peripheral first-hexagonal-unit tubes and a central first-hexagonal-unit tube, wherein the six peripheral first-hexagonal-unit tubes surround the central first-hexagonal-unit tube in a juxtaposed, hexagonal configuration, further wherein:
• each first hexagonal unit comprises first-hexagonal-unit tube sets, wherein each first-hexagonal-unit tube set comprises constituent first-hexagonal-unit tubes, wherein the constituent first-hexagonal-unit tubes comprise a respective first-hexagonal-unit tube of the first-hexagonal-unit tubes and, optionally, one or more internal first-hexagonal-unit tubes wherein each internal first-hexagonal-unit tube is in an entirely immediately nested and concentric configuration with at least one other constituent first-hexagonal-unit tube, further wherein:
• each first-hexagonal-unit tube set consists of the respective first-hexagonal-unit tube of the first-hexagonal-unit tubes, further wherein:
• the first-hexagonal-unit tubes of each first hexagonal unit have a diameter Din of from 20 μm to 50 μm, a thickness t of from 0.1 μm to 10 μm, and define a gap g of from 0 μm to 10 μm.

A foam comprising tubes substantially aligned longitudinally in a first direction, wherein:

• each tube defines an outer wall and an inner wall, and each tube comprises an entangled bundle of carbon nanotubes substantially aligned longitudinally in the first direction;
• and
• tubes in at least a subset of the tubes are positioned with respect to each other to form one or more first hexagonal units, wherein each first hexagonal unit comprises first-hexagonal-unit tubes, wherein the first-hexagonal-unit tubes comprise six peripheral first-hexagonal-unit tubes and a central first-hexagonal-unit tube, wherein the six peripheral first-hexagonal-unit tubes surround the central first-hexagonal-unit tube in a juxtaposed, hexagonal configuration, further wherein:
• each first hexagonal unit comprises first-hexagonal-unit tube sets, wherein each first-hexagonal-unit tube set comprises constituent first-hexagonal-unit tubes, wherein the constituent first-hexagonal-unit tubes comprise a respective first-hexagonal-unit tube of the first-hexagonal-unit tubes and, optionally, one or more internal first-hexagonal-unit tubes wherein each internal first-hexagonal-unit tube is in an entirely immediately nested and concentric configuration with at least one other constituent first-hexagonal-unit tube, further wherein:
• the constituent first-hexagonal-unit tubes comprise the respective first-hexagonal-unit tube of the first-hexagonal-unit tubes and the one or more internal first-hexagonal-unit tubes wherein each internal first-hexagonal-unit tube is in the entirely immediately nested and concentric configuration with the at least one other constituent first-hexagonal-unit tube.

A method of using an article of manufacture, the method comprising subjecting the article of manufacture to an oblique impact, the article of manufacture comprising a foam comprising tubes substantially aligned longitudinally in a first direction, wherein:

• each tube defines an outer wall and an inner wall, and each tube comprises an entangled bundle of carbon nanotubes substantially aligned longitudinally in the first direction;
• and
• tubes in at least a subset of the tubes are positioned with respect to each other to form one or more first hexagonal units, wherein each first hexagonal unit comprises first-hexagonal-unit tubes, wherein the first-hexagonal-unit tubes comprise six peripheral first-hexagonal-unit tubes and a central first-hexagonal-unit tube, wherein the six peripheral first-hexagonal-unit tubes surround the central first-hexagonal-unit tube in a juxtaposed, hexagonal configuration, and further wherein:
• the article is configured to cover at least a portion of an object and to attenuate an external force acting on the object.