10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
3D Nano-Printing via Electric-Field Assisted Aerosol Lithography
WOOIK JUNG, Yoon-ho Jung, Mansoo Choi, Seoul National University
Abstract Number: 1086 Working Group: Materials Synthesis
Abstract Ion assisted aerosol lithography (IAAL) is an aerosol-based 3 dimensional (3D) assembly technique, which utilizes electrostatic focusing effects to manipulate the trajectory of incoming charged nanoparticles. (Kim et al., 2006; Lee et al., 2010; Choi et al., 2015.) Charged aerosols can be directed into openings in photoresist patterns or apertures in masks, making it possible to produce 3D nanoparticle structures whose shapes are defined by the cross-section of the openings in the photoresist layer or the mask.
Building upon this, here we show that translating the mask during the nanoparticle deposition process holds promises to be a novel 3D nano-printing technique. The shapes of the 3D nanoparticle structures are now determined not only by the cross-section of the mask openings, but also by the mask trajectory. Interestingly, we found that varying the horizontal mask translation speed leads to two distinct process regimes: ‘3D growth’ mode at slower translation speeds and ‘3D writing’ mode at faster translation speeds.
In ‘3D printing’ mode, high aspect ratio nanowires can be assembled by vertical upward translation of the mask during particle deposition. In principle, the process can continue indefinitely by matching the mask translation speed to the vertical growth rate of the structures. Adding horizontal components in the mask motion allows for creation of structures with various 3D shapes, such as slanted pillars or helices. In ‘3D writing’ mode, faster horizontal translation of the mask causes the particles to land next to the existing clusters rather than being deposited on them. This enables particle assembly whereby the structures do not lift off vertically from the substrate. Multiple sweeps of a given trajectory while depositing particles allow the clusters to grow in thickness and become ‘walls’.
In addition to the presented capability of directly printing 3D shapes using this technique, the ability to switch the aerosol material on demand with relative ease contributes to the expected versatility of this process, and further development and fine tuning will benefit applications that require multi-material 3D nanostructures.
This work was supported by Global Frontier R&D Program on Center for Multiscale Energy System by National Research Foundation (NRF) under the Ministry of Science, ICT and Future Planning, Korea (Grant no.2012M3A6A7054855).
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