Clean, fast and scalable transfer of ultrathin/patterned vertically-aligned carbon nanotube arrays

Abstract

The difficulty of transferring vertically-aligned carbon nanotube (VACNT) arrays onto specific substrates limits their use in many fields, for instance as thermal interface materials or electrical interconnects in microelectronics. Current transfer techniques are either limited by the type and shape of the target substrate, or their inability to transfer patterned and thin VACNT arrays. Here, we report a simple and clean press transfer method that does not use transfer media, and involves only pressing and lifting steps. This method enables not only the transfer of patterned and very thin VACNT arrays but also the tight adhesion of the arrays onto various flat or curved target substrates. Flexible and transparent electrodes were fabricated by transferring inter-digitated VACNT patterns onto a PET substrate. VACNT arrays with a thickness of 20 μm were transferred onto target substrates cleanly, showing a very low thermal resistance of ∼26 K mm2 W−1. The transferred clean, thin VACNT arrays show good heat dissipation as thermal interface material when integrated into a desktop computer CPU cooling system.