Enhanced Reliability MEMS Deformable Mirrors for Space Imaging Applications
Project Description
The goal of this project is to develop and demonstrate a reliable, fault-tolerant wavefront control system that will fill a critical technology gap in NASA's vision for future coronagraphic observatories. The project outcomes include innovative advances in component design and fabrication and substantial progress in development of high-resolution deformable mirrors (DM) suitable for space-based operation. Space-based telescopes have become indispensible in advancing the frontiers of astrophysics. Over the past decade NASA has pioneered coronagraphic instrument concepts and test beds to provide a foundation for exploring feasibility of new approaches to high-contrast imaging and spectroscopy. From this work, NASA has identified a current technology need for compact, ultra-precise, multi-thousand actuator DM devices. Boston Micromachines Corporation has developed microelectromechanical systems (MEMS) DMs that represent the state-of-the-art for scalable, small-stroke high-precision wavefront control. The emerging class of high-resolution DMs pioneered by the project team has already been shown to be compact, low-power, precise, and repeatable. This project will develop a system that eliminates the leading cause of single actuator failures in electrostatically-actuated wavefront correctors – snap-through instability and subsequent electrode shorting and/or adhesion. To achieve this we will implement two innovative, complementary modifications to the manufacturing process that were proven successful in Phase I. We will develop a drive electronics approach that inherently limits actuator electrical current density generated when actuator snap-down occurs, and we will modify the actuator design to mitigate adhesion between contacting surfaces of the actuator flexure and fixed base electrode in the event of snap-down. This project will results in a MEMS DM with 2048 actuators and enhanced reliability driven by current-limiting drive electronics.
More »Anticipated Benefits
Space based astronomical imaging systems are inherently challenged by the need to achieve diffraction-limited performance with relatively lightweight optical components. Given the current constraints on fabrication methods, it is necessary to develop new methods of manufacture to increase reliability and prevent single actuator failures. These higher-quality deformable mirrors will enable diffraction-limited performance for many space-based optical systems such as space-based observatories, interferometric telescopes and coronagraphic instruments for programs such as EPIC, TPF-C, TPF-I and PECO. By providing wavefront control and correcting for static and thermally induced aberrations of larger optics in a space-based optical platform, the use of a space-qualified MEMS DM will result in a significant performance improvement. Producing a more reliable and robust MEMS DM will also have a significant benefit for non-space-based optical instruments. BMC has had success developing arrays up to 4096 elements for the Gemini Planet Imager and with further research can achieve fewer actuator failures during the manufacturing process and better reliability during use.
Reliable, small stroke, high precision deformable mirrors and associated drive electronics have a few commercial applications. The following applications apply to all Boston Micromachines mirrors that benefit from new manufacturing processes developed which increase reliability. Space surveillance: BMC has success developing arrays up to 4096 elements for astronomy which can be used for space-based systems. These programs are funded by Department of Defense administrations with classified agendas. Optical communication: Lasercomm systems would benefit from this new architecture for long-range secure communication. Microscopy: The capabilities of non-adaptive optics-enabled Optical Coherence Tomography(OCT) and Scanning Laser Ophthalmoscopy(SLO) devices have reached their limits. By increasing reliability, users will be able to utilize high-resolution equipment for use in detecting disease in uncontrolled environments. Other modalities affected include two-photon excitation fluorescence (TPEF) and coherent anti-stokes Raman spectroscopy (CARS). Pulse-Shaping: Laser science strives to create a better shaped pulse for applications such as laser marking and machining, and material ablation and characterization. The use of a highly reliable, high-actuator count array for these purposes will enable new science and confidence that equipment is usable in non-ideal environments.
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Boston Micromachines Corporation | Lead Organization | Industry | Cambridge, Massachusetts |
| Jet Propulsion Laboratory (JPL) | Supporting Organization | FFRDC/UARC | Pasadena, California |
Primary U.S. Work Locations
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California
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Massachusetts
