High‐Resolution, Parallel Patterning of Nanoparticles via an Ion‐Induced Focusing Mask

Abstract

An ion-induced focusing mask under the simultaneous injection of ions and charged aerosols generates invisible electrostatic lenses around each opening, through which charged nanoparticles are convergently guided without depositing on the mask surface. The sizes of the created features become significantly smaller than those of the mask openings due to the focusing capability. It is not only demonstrated that material-independent nanoparticles including proteins can be patterned as an ordered array on any surface regardless of the conductive, nonconductive, or flexible nature of the substrate, but also that the array density can be increased. Highly sensitive gas sensors based on these focused nanoparticle patterns are fabricated via the concept.

Assembly of Nanoparticles: Towards Multiscale Three-Dimensional Architecturing

“…Fig. 4(c) shows that human IgG was convergently deposited onto the center regions within 2-µm line patterns of SiO 2 , which indicates the possibility of the selective immobilization of proteins onto the desired locus 88,89) . The fluorescence image of Alexa 488 through confocal laser scanning microscope (CLSM) in Fig.…”

“…Actually, Kim et al 45) and You et al 89) demonstrated that IAAL was effectively applicable to a substrate with a nonconducting surface as well as a conducting substrate. However, the focusing capability disappeared when the thickness of a SiO 2 layer on a silicon substrate became larger than a few micrometers according to the simulation results 89) .…”

“…Numerical simulations for the IAAL system can be done by solving this Langevin equation and the detailed simulation method and its results can be found in other studies 89,90) .…”

“…You et al 89) introduced a way of using a patterned dielectric mask in the IAAL process that does not need any surface modifications to make prepatterns for a deposition. They replaced the patterned photoresist layer with a patterned dielectric mask such as silicon nitride or epoxy masks, which enabled to eliminate multiple steps of fabricating photoresist patterns and its removal process.…”

Wire-in-Hole-Type Spark Discharge Generator for Long-Time Consistent Generation of Unagglomerated Nanoparticles

“…Furthermore, spark discharge generation can produce nanoparticles using diverse materials having varied properties, such as bimetallic and mixed metallic nanoparticles (Watters et al 1989;Byeon et al 2008), and nanocomposites (Kala et al 2013). In addition, this technique has been utilized to generate various types of charged aerosols (Borra et al 1998), which enable the positioning of particles at precise locations on a dielectric surface (Krinke et al 2001) and the fabrication of nanostructures via controlled electric field (Kim et al 2006;You et al 2010;Lee et al 2011;Jung et al 2014).…”