Linear micromechanical stepping drive for pinhole array positioning

Abstract

A compact linear micromechanical stepping drive for positioning a 7 × 5.5 mm2 optical pinhole array is presented. The system features a step size of 13.2 µm and a full displacement range of 200 µm. The electrostatic inch-worm stepping mechanism shows a compact design capable of positioning a payload 50% of its own weight. The stepping drive movement, step sizes and position accuracy are characterized. The actuated pinhole array is integrated in a confocal chromatic hyperspectral imaging system, where coverage of the object plane, and therefore the useful picture data, can be multiplied by 14 in contrast to a non-actuated array.

2D stepping drive for hyperspectral systems

“…In the example of figure 1 between 12-18 µm, the overlapping areas between the steps are higher than is necessary for a full scan of the object plane. Scaling down the pitch and diameter of the pinhole array can greatly reduce the scanning time [9]. Further reduction of the sampling time can be expected with an optimization of the control signals.…”

“…In the first step, a linear micromechanical stepping drive was implemented, where a special pinhole array design guarantees a complete imaging of the object plane [8,9]. To further enhance the spectral separation with a higher pinhole distance, a 2D microdrive is needed.…”