Electrospray ionization is a technique widely used in mass spectrometry. Almost every material, specifically large molecules like proteins or polymers can be ionized directly out of solution. During the ionization process molecules are not fragmented. In this work a prototype apparatus for creating three-dimensional patterns in a ultra high vacuum environment using an electrospray ion source was optimized for higher ion currents hence deposition rate by improving the core component of the apparatus, an electrodynamic ion funnel. The major improvements are a redesigned heated vacuum inlet, modified gas flow inside the ion funnel because of sealing the ion funnel against perpendicular gas flow and a better measurement setup for the transmitted current. The transmission of the ion funnel was improved from 25% to 82% resulting in ion currents of up to 7nA (500pA before advancements) focused through the ion funnel. At this rate an area of 1 cm² can be coated with a molecular monolayer of Cytochrome C in 64 minutes.

This study focuses on novel approaches to the modeling and construction of devices used in ion beam and vacuum systems. Turbulent computational fluid dynamics simulations were performed to model the air flow into an ion funnel system. The results of these simulations were coupled one-way with electrodynamics simulations of the fields generated by the ion funnel. Using the turbulence kinetic energy (k), a spatially varying estimation of the fluctuating component of the velocity field was calculated. These resulting simulations more accurately predicted the ion transmission through the system. Using fused deposition modeling (FDM) novel construction methods for the ion funnel and the vacuum chamber components the ion funnel system utilizes were developed. An FDM fabricated frame, in the shape of the ion funnel, was quickly and inexpensively produced. This frame supported a flexible printed circuit board that served as both the lenses of the ion funnel and power distribution circuit. The transmission of ions was as good as the traditionally constructed ion funnel. The device cost and weighed less and had lower intrinsic impedance, requiring less power to be driven. FDM was also used to produce vacuum components by post-processing using electroplating. Initial tests to determine whether electroplating would adequately produce a hermetic seal for vacuum components were performed. It was observed that thinner plated components could not withstand the stresses required from the gaskets and flanges to adequately seal, subsequently cracking. Thicker samples adequately sealed against atmosphere and maintained this seal over the entire test period. A proof of concept KF-25 full nipple was produced and processed using electroplating. The device was able to reach and ultimate pressure of 1 x 10-6 Torr, however, it was not able to reach the ultimate pressure of the chamber, which was 5 x 10-7 Torr due to the inability to be adequately cleaned of contaminant water.

This PhD dissertation reports the development of miniature ion optics components of a mass spectrometer (MS) with the ultimate goal to lay the foundation for a compact low-power micromachined MS (µMS) for broad-range chemical analysis. Miniaturization of two specific components a) RF ion traps and b) an ion funnel have been investigated and miniature low-power versions of these components have been developed and demonstrated successfully in lab experiments. Power savings, simpler electronics and packaging schemes required to operate the micro-scale RF cylindrical ion traps have been the key motivation driving this research. Microfabricated cylindrical ion traps (µCITs) and arrays in silicon, silicon-on-insulator and stainless steel substrates have been demonstrated and average power of as low as 55 mW for a low mass range (28 to 136 amu) and mass spectra with better than a unit-mass-resolution have been recorded. For the ion funnel miniaturization effort, simple assembly, small form factor and ease of integration have been emphasized. A simplification of the conventional 3D ion funnel design, called the planar ion funnel, has been developed in a single plate and has been tested to demonstrate ion funneling at medium vacuum levels (1E-5 Torr) using DC voltages and power less than 0.5 W. Miniaturization of these components also enables use of other novel ion optics components, packaging and integration, which will allow a new class of µMS architectures amenable for radical miniaturization.