| Precision 1D and 2D micro positioners using electrothermal actuators and capacitive position sensors are reported. The sensors enable feedback controlled operation and precise and repeatable positioning. Compliant displacement amplifiers are used to further improve the position sensing accuracy.; The initial investigations utilize an enhanced silicon-on-insulator (SOI) process that allows electrical isolation between structures; 60-μm-thick etched features and silicon nitride filled isolation plugs are presented. The devices produce displacement sensitivity of 0.333fF/nm over a range of 10μm, and a full displacement range of 19.0μm. The displacement amplifier gain is 3.4. The actuator generates at least 9mN at the peak displacement. These results indicate that sub-nanometer resolutions can be achieved with the integration of on-chip electronics.; Micromachined 2D positioners are applied to the surface scanning Kelvin probe microscopy technique; a Kelvin-probe-on-a-chip with integrated probe tip and actuators is realized. Experimental scan results are presented, together with the results from the redesigned second-generation micro-Kelvin-probe. |
