Low voltage large stroke bipolar tri-electrode electrostatic actuator for deformable mirrors in adaptive optics
Bibliographic record
Abstract
Image distortion is one of the most common problems of optical receivers. Adaptive Optics (AO) technology was invented to solve that issue for ground-based telescopes. The deformable mirror (DM) is the corrector which is being used to correct the aberrated received image in an AO system. The arrays of actuators and the flexible mirror face sheet are the two main elements of a DM. In this thesis, a tri-electrode electrostatic actuator was studied which is comprised of one moving MEMS electrode and two fixed controlling electrodes. The actuator is primarily beneficial for usage in an array of actuators for DMs, since only one common high-voltage electrode is employed as the background electrode for all actuators in the array, and the movement of each individual actuator can be controlled by an individual low voltage electrode. The tri-electrode topology, and the additionally presented extended electrode tri-electrode configurations, are designed such that they can be utilized for other applications such as MEMS switches. In this work, all the design parameters of the tri-electrode actuator were studied in simulation using the finite element method and restoring spring force method, as well as experimentally. The design studies were dimensionless. Therefore, the optimizations can be used for an actuator of any size. The studies showed that the controlling voltage of the actuator can be decreased significantly. For one specific design, it was shown that the controlling voltage is almost four times smaller than for a conventional parallel plate electrostatic actuator. The maximum displacement of the actuator can be enhanced significantly compared to that of the conventional configuration. The increased range of motion can be bidirectional, and for one specific case it was 2.5 times larger than for the conventional actuator using the extended electrode design. Two silicon MEMS actuators were designed in order to experimentally verify the simulation studies. The measurements showed a close agreement between the simulations and the demonstrated prototype designs. Secondary research was also performed to study the issues in building a tri-layer flexible mirror that can be utilized as the face sheet for DMs. The conducted stress analysis investigations result in valuable conclusions and a fabrication recipe was developed to enable tensile stress mirrors. The recipe was used to build tensile stress metal-polymer-metal tri-layer structures to enable wrinkle free mirrors, and a high level of smoothness as it is necessary for a flexible mirror face sheet.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".