Breakthrough improvements in simplicity and
reductions in the size of mass spectrometers are needed
for high-consequence fieldable applications, including
error-free detection of chemical/biological warfare
agents, medical diagnoses, and explosives/contraband
discovery. These improvements are most likely to be
realized with the reconceptualization of the mass
spectrometer, rather than by incremental steps towards
miniaturization.
Microfabricated arrays of mass analyzers represent
such a conceptual advance. A massively parallel array of
micrometer-scaled mass analyzers on a chip has the
potential to set the performance standard for hand-held
sensors due to the inherit selectivity, sensitivity, and
universal applicability of mass spectrometry as an
analytical method.
Sandia has designed and built an ion trap mass
analyzer consisting of 1 x 106 micron-sized
cylindrical ion traps. We have microfabricated massive
parallel ion trap arrays consisting of traps with r
0 = 1, 2, 5 and 10 µm. The instrument is the
result of a conceptually radical change in the scaling
of both size and number of ion traps and in the
fabrication approach compared to previous embodiments.
The array of micro-ion traps is a freely suspended air
gap structure fabricated in tungsten using silicon-based
semiconductor and MEMS microfabrication methods. Both
ITSIM and SIMION simulations of an
r0 = 1 µm
CIT indicate useful trapping efficiencies at low rf
voltages (from a few volts to a few 10's of volts),
however the influence of initial ion temperatures and rf
heating due to nonlinear fields was found to be of added
(and potentially useful) importance on this size scale.
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Duroid Board
Cylindrical Ion Trap 
Cross Section of Cylindrical Ion Trap 
Cross Section of Cylindrical Ion Trap 
SEM Micrograph of Ion Trap Array
SolidWorks 3D Representation
SolidWorks 3D Representation 