Optimization of Comb-Drive Actuators [Nanopositioners for probe-based data storage and musical MEMS]

The era of infinite storage seems near. To reach it, data storage capabilities need to grow, and new storage technologies must be developed.This thesis studies one aspect of one of the emergent storage technologies: optimizing electrostatic combdrive actuation for a parallel probe-based data storage system. It is no longer possible to store all created information. New storage technologies must be developed as current commercial technologies reach their fundamental limits. One promising technology is parallel probe-based data storage, using a nanometre-scale probe to write data on a moving platform. The working principle is very similar to that of a record player applied in parallel on the nano scale. In order to access all bits on the storage medium, a nano-positioner, or scanner, is used to move the storage medium relative to the read-out probes. Several nano-positioner designs for probe data storage are found in the literature. It is not clear which actuator type (electromagnetic, electrostatic, or piezoelectric) is most suited for probe data storage. We replaced the electrodynamic actuators by comb-drives in the scanner prototype by IBM, to enable a direct comparison. e comb-drive’s areal efficiency is low, due to a relatively low electrostatic force. e comb-drive finger profile is optimized for probe data storage, for an increased shock resistance. e suitability of electromagnetic and electrostatic actuation is, among others, determined by their energy consumption.Three (partly) hypothetical scanner designs using electrodynamic, electromagnetic and electrostatic comb-drive actuators are described. Their performance is approximately equal, however electrostatic comb-drive actuation requires an order of magnitude less energy. Equations are presented for further investigations into the performance and energy consumption of the different actuation types for different file-system use cases. We succeeded in making music with MEMS structures, and named our microinstrument ‘the micronium’. Due to fabrication inaccuracies, the instrument is outof- tune and requires tuning. Besides teaching students about MEMS technology in a fun way, the micronium succeeded in presenting MEMS technology to a broad audience.