Atomistic simulations on nanoimprinting of copper by aligned carbon nanotube arrays under a high-frequency mechanical vibration.

Nanoimprinting behaviors of copper substrates and double-walled carbon nanotubes with interwall sp 3 bonds are investigated using molecular dynamics simulations. A high-frequency mechanical vibration with various amplitudes is applied on the carbon nanotube (CNT) mold and copper substrate in different directions. Results show that exciting mechanical resonances both on the CNT and substrate drastically decrease the maximum imprint force and interfacial friction up to 50% under certain amplitudes. Meanwhile, it is demonstrated that defects occur in the {111} plane in the copper substrate during nanoimprinting. For different CNT array densities, a higher grafting density needs more imprint force to transfer patterns. The maximum imprint force for a large range of CNT array densities can be reduced by vibrational perturbations, while reduction rates depend on the CNT grafting density. This work sheds deep insights into the nanoimprint process at the atomic level, suggesting that vibration perturbation is an effective approach for improving the nanoimprinting accuracy and preventing the fracture of nanopatterns.