Circular arrays of polymer-based miniature rectilinear ion traps

The design and operation of an annular array of parallel, miniature rectilinear ion traps (RITs) is discussed. Stereolithography apparatus (SLA), a previously validated method for ion trap fabrication, was applied here to construct an array of mass analyzers and their mounting hardware. Two versions of the array were tested, using either six or twelve stretched RITs (x₀ = 1.66 mm, y₀ = 1.33 mm, z = 16.66 mm) mounted in parallel about the circumference of a circle with the interior and exterior x-electrode planes oriented tangential to the inner and outer annulus rings, respectively. The arrangement of the ion traps is such that the ions are radially ejected just above the throat of a centrally located electron multiplier detector into which they are accelerated. The mass analyzer array was mounted in a custom vacuum manifold. The resolution, mass-to-charge ratio (m/z) range, and MS/MS capabilities were tested using electrospray ionization (ESI). The devices were tested in two configurations: (i) separate ion sources for each trap, and (ii) a single ion source for the entire array.