This dissertation presents advances in the development of planar electrode ion traps. An ion trap is a device that can be used in mass analysis applications. Electrode surfaces create an electric field profile that trap ionized molecules of an analyte. The electric fields can then be manipulated to mass-selectively eject ions out of the trap into a detector. The resulting data can be used to analyze molecular structure and composition of an unknown compound. Conventional ion traps require machined electrode surfaces to form the electric trapping field. This class of electrode presents significant obstacles when attempting to miniaturize ion traps to create portable mass spectrometers. Machined electrodes lose required precision in shape, smoothness, and alignment as trapping dimensions decrease. Simplified electrode geometries are essential to open the way to miniaturized ion traps. The planar electrode ion trap presents a simplified geometry that utilizes photolithography processes in its fabrication. Patterns of electrodes are patterned on a planar ceramic substrate. Electric fields generated by these patterns can be nearly identical to those of ideal ion traps. The microfabrication processes involve the challenge of patterning on ceramic, patterning on two sides of a substrate, and patterning on a substrate with high topographic features. Four successful designs of planar ion traps are presented in this work: the planar Paul, toroidal, coaxial, and linear ion trap. These four designs have different strengths and weaknesses. The planar Paul trap is simpler to design and operate, the toroidal has a larger ion storage volume and so can be a more sensitive instrument, and the coaxial trap is a hybrid planar Paul and toroidal trap. The linear trap combines the simplicity of the planar Paul trap with the increased storage capacity of the toroidal trap. This work presents how these four designs advance work in miniaturized ion traps. In addition, microfabrication techniques and trap performance for these designs are presented.



College and Department

Ira A. Fulton College of Engineering and Technology; Electrical and Computer Engineering



Date Submitted


Document Type





Brett Hansen, mass spectrometry, ion trap, microfabrication, lithography, high topography, toroidal ion trap, linear ion trap, MEMS