title: Reliable Diameter Control of Carbon Nanotube Nanobundles Using Withdrawal Velocity.
abstract: Carbon nanotube (CNT) nanobundles are widely used in nanoscale imaging, fabrication, and electrochemical and biological sensing. The diameter of CNT nanobundles should be controlled precisely, because it is an important factor in determining electrode performance. Here, we fabricated CNT nanobundles on tungsten tips using dielectrophoresis (DEP) force and controlled their diameters by varying the withdrawal velocity of the tungsten tips. Withdrawal velocity pulling away from the liquid-air interface could be an important, reliable parameter to control the diameter of CNT nanobundles. The withdrawal velocity was controlled automatically and precisely with a one-dimensional motorized stage. The effect of the withdrawal velocity on the diameter of CNT nanobundles was analyzed theoretically and compared with the experimental results. Based on the attachment efficiency, the withdrawal velocity is inversely proportional to the diameter of the CNT nanobundles; this has been demonstrated experimentally. Control of the withdrawal velocity will play an important role in fabricating CNT nanobundles using DEP phenomena.
authors: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro. Nam-Gu, Pohang, Gyeongsangbuk-do, 790-784, Republic of Korea.
authors: Jung Hwal
authors: JH
authors: Shin
authors: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro. Nam-Gu, Pohang, Gyeongsangbuk-do, 790-784, Republic of Korea.
authors: Kanghyun
authors: K
authors: Kim
authors: Department of Mechanical Design Engineering, Andong National University, Andong, Gyungbuk, 760-749, Republic of Korea.
authors: Taechang
authors: T
authors: An
authors: Department of Mechanical Engineering, Korea National University of Transportation, 50 Daehak-Ro, Chungju, Chungcheongbuk-do, Chungcheongbuk-do, 380-702, Republic of Korea. w.choi@ut.ac.kr.
authors: WooSeok
authors: W
authors: Choi
authors: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro. Nam-Gu, Pohang, Gyeongsangbuk-do, 790-784, Republic of Korea. limmems@andong.ac.kr.
authors: Geunbae
authors: http://orcid.org/0000-0002-7062-3575
authors: G
authors: Lim
keywords: Attachment efficiency; CNT nanobundle; Capillary force; Carbon nanotube (CNT); Withdrawal velocity; van der Waals force