Integrated Micromachinery -- Moving Structures on Silicon Chips

Some basic issues of integrated micromachinery -- microassembly, material, and actuation, have been studied. This manuscript describes four new techniques in surface micromachining: l. in situ assembly and the use of multiple sacrificial layers, 2. self-constraining and the exploitation of conformal deposition, 3. the introduction of hemispherical bushings to handle adhesion problem in released structures, and 4. thin-film, three-dimensional helical springs formed by strain gradients in the films. We also introduce four methods for mechanical-property characterization of thin films: 1. x-ray analysis to determine the orientation-distribution function (ODF) and thereby to interpret film properties, 2. spring-constrained pin joints for characterization of ultimate strength, 3. self-destructing bridges for fracture-strength characterization, and 4. spiral structures for strain-gradient characrerization. Finally, this research also demonstrates for the first time the feasibility of rorational electrostatic micromotors.