High-aspect-ratio silica nozzle fabrication for nano-emitter electrospray applications

Review on water electro-sprays and applications of charged drops with focus on the corona-assisted cone-jet mode for High Efficiency Air Filtration by wet electro-scrubbing of aerosols

“…Here ES is used as an ion source to produce ionized species from liquid droplets, then analyzed either (i) by mass spectrometry, referred as ES Ionization-MS (Thompson et al, 1984;Yamashita et al, 1984;Whitehouse et al, 1985;Fenn et al, 1990;Wilm et al, 1994;Xu X et al, 1996;Juraschek et al, 1998;Pozniak et al, 2004;Loo et al, 2005;Marginean et al, 2007;Pozniak et al, 2007) used for macromolecules analysis and quantification near atmospheric pressure by online HPLC MS/MS, in both polarities or (ii) by mobility analysis of so-produced droplets/dried residues by ES-DMA for Differential Mobility Analyzers or as GEMMA for Gas-phase Electrophoretic Mobility Molecular Analyzer (Lewis et al, 1994;Kaufman et al, 1996;Mouradian et al, 1997;Kaufman, 1998;Kaufman et al, 1998;Kaufman, 2000;Bacher et al, 2001;Tsai et al, 2008;Tsai et al, 2013;Tai et al, 2014;You et al, 2014;Almaier, 2018). These analytical methods are still under development with new microfluidic facilities for "nanoemitter" to reach unequaled sensitivity for biomolecules like DNA, lipoprotein at sub-nL.min -1 (Bacher et al, 2001;Marginean et al, 2007;Wang L et al, 2007b;Gibson et al, 2009;Marginean et al, 2014).…”

Compact multiplexing of monodisperse electrosprays

“…On the basis of the ES source arrangement, these approaches fall in three categories: linear array, multi-jet mode and planar array. The linear array MES simply entails duplication of several capillaries operating in parallel by "brute force" (Rulison & Flagan, 1993), by etching of fused silica capillaries (Kelly, Page, Tang, & Smith, 2007), by soft lithography on PDMS (Kim & Knapp, 2001), or by silicon microfabrication (Kim, Guo, Yang, & Wang, 2007;Wang et al, 2007). These linear systems were demonstrated reliably with a limited number of sources (up to 20), although the linear packing density can reach 1000 sources/cm.…”

Electrospray: More than just an ionization source

“…In addition to stainless steel, paper platforms [11], disposable pipette tips [12], plant leaves [13], carbon fibers [14], PDMS [15], fused silica [16], ball pen [17], ferrofluid [18], and many other materials have been proved to function as emitters for ES. Moreover, multiple designs have been developed to enhance throughput [19][20][21][22][23][24][25] or to neutralize the charges of droplets by using two sprays with opposite polarities [26,27].…”