Programmable Stepwise Collective Magnetic Self-Assembly of Micropillar Arrays
- Authors
- Park, Jeong Eun; Park, Sei Jin; Urbas, Augustine; Ku, Zahyun; Wie, Jeong Jae
- Issue Date
- Feb-2022
- Publisher
- AMER CHEMICAL SOC
- Keywords
- magnetic composites; micro arrays; soft actuators; self-assembly; stimuli-responsive polymers
- Citation
- ACS NANO, v.16, no.2, pp.3152 - 3162
- Indexed
- SCIE
SCOPUS
- Journal Title
- ACS NANO
- Volume
- 16
- Number
- 2
- Start Page
- 3152
- End Page
- 3162
- URI
- https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/188652
- DOI
- 10.1021/acsnano.1c10844
- ISSN
- 1936-0851
- Abstract
- Chain-like magnetic self-organizations have been documented for micron/submicron-scale magnetic particles. However, the positions of the particles are not stationary in a sustaining fluid owing to Brownian translational motion, resulting in irregular magnetic self-assembly. Toward the development of a programmable and reversible magnetic self-assembly, we report a stepwise collective magnetic self-assembly with periodic polymeric micropillar arrays containing magnetic particles. Under an external magnetic field, the individual micropillar acts as a micromagnet; magnetic polarities of embedded ferromagnetic particles are arranged in the same direction. The nearest pillar tops undergo a pairwise assembly owing to the anisotropic quadrupolar interaction, whereas the pillar bases remain stationary because of the presence of a magnetically inert substrate. By increasing the magnetic flux density, a collective quad-body assembly of vicinal paired micropillars is accomplished, finally leading to long-range connectivity of the pillar tops. Simple evaporation of the polymeric solution yields shape-fixation of the connected micropillar architectures even after magnetic fields are removed. We investigate geometric effects on this stepwise collective magnetic self-assembly using rectangular, square, and circular micropillars. Also, we demonstrate spatially selective magnetic self-assembly (e.g., arbitrary letters) using a masking technique. Finally, we demonstrate on-demand programming of bidirectional liquid spreading through long-range ordered magnetic self-assembly.
- Files in This Item
-
Go to Link
- Appears in
Collections - 서울 공과대학 > 서울 유기나노공학과 > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.