Long-Stroke, Micromachined, Linear Actuator for Positioning Optical Components

NASA requires micro-miniature precision stages which can be used for positioning of small lightweight devices such as optical mirrors. SatCon is proposing, as the essential actuator element, a micromachined, electrostatically deflected, compound cantilever. The cantilevers will be micromachined with the deep etch capabilities of the LIGA process at the Center for Advanced Microstructures (CAMD) of Louisiana State University. The cantilevers can be multiply-arranged for full-tilt control and linear positioning of small lightweight devices such as optical mirrors. Mass production is practical since molds for a complete six-degree-of-freedom can be fabricated in a single run. Since each actuator element in a set can be independently controlled, this allows not only aiming of an array of mirrors but also variable control of focal length. The development of variable focus, compact optical reflecting, and eventually refracting, elements would have significant application in consumer applications such as cameras, medical devices, and video technology. In Phase I, a geometrical design will be developed along with a viable fabrication technique consistent with the LIGA process. The efficacy of key aspects of these designs will be assessed through actual fabrication of test structures at the LIGA facility. For Phase II, prototype actuators will be fabricated and evaluated.