Infiltrated carbon nanotubes

A method, comprising:

• growing a carbon nanotube (CNT) structure on a substrate, wherein the CNT structure comprises:
• a first CNT;
• and
• a second CNT, wherein the first CNT and the second CNT are vertically aligned, wherein, during growing the first CNT or the second CNT includes:
• flowing the ethylene at approximately fifteen parts per minute;
• and
• flowing the hydrogen at approximately forty parts per minute;
• and
• infiltrating bulk carbon between the first CNT and the second CNT, the bulk carbon adhering to the first CNT and the second CNT, wherein the infiltrating comprises heating the first CNT and the second CNT in the presence of a gas mixture to a temperature between approximately 800 to 950° C., wherein:
• the gas mixture comprises:
• ethylene flowing at approximately one part per minute;
• and
• hydrogen flowing at approximately two parts per minute;
• the gas mixture is flowed over the first CNT and the second CNT for an amount of time ranging from 1 minute to 24 hours;
• and
• the infiltrating strengthens the carbon nanotube structure such that when the carbon nanotubes are cooled, the carbon nanotubes do not delaminate from the substrate;
• and
• cooling the first CNT and the second CNT in the presence of argon to approximately 300° C.