Validating models of a physical system with experiments : electrostatic actuators in electrolytes
Abstract/Contents
- Abstract
- The construction and validation of models for systems is essential to engineering. This requires accurate mathematical representations of relevant processes, parameter and/or state estimation in order to inform models, high quality experiments with which to validate these models, and a formal evaluation of the ability of model's to explain a physical system. Typically, an individual research project in the context of academia focuses on one or two of these steps. In the work done in this thesis, we perform these steps in concert, and apply it to the case of an electrostatic comb-drive actuator in electrolytes. Electrostatic comb-drive actuators in electrolytes have many potential applications. Two applications, in particular, are found in literature. The most commonly cited is characterizing the mechanical properties of diverse structures at small scales. In particular, biological cells. The mechanical properties of cells are critical to their health, and can be implied by observing their behavior in response to external forcing. Electrostatic comb-drive actuators in conducting liquids also have potential in microfluidic systems. In particular, they can be used in microfluidic systems designed for drug delivery, and the mechanical manipulation of cells. Maximizing the utility of these devices for such applications requires robust methods for operating electrostatic actuators in electrolytes, and the creation of accurate models for these devices. Electrostatic actuators are typically operated with DC voltages. In electrolytes, an ionic shield forms on the actuator surface's under the influence of DC voltages, preventing motion. Previous studies discovered that this effect could be overcome by applying AC voltages with sufficiently high frequencies. Lumped circuit models were subsequently developed that accurately captured the general behavior of electrostatic actuators with comb-drive and parallel plate configurations respectively. However, these models had limited quantitative accuracy at low and intermediate frequencies of the AC signal. We develop models of the comb-drive actuator in electrolytes that are accurate over a wide range of frequencies, and that will facilitate accurate control of these actuators in both the context of deforming cells, and of actuation in microfluidic systems. We also develop a method of parameter estimation that simultaneously performs optimization and uncertainty quantification, and allows us to comment on the generalizability, informativeness, and best fit of our models, with respect to the physical system.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Dibua, Ohiremen L |
|---|---|
| Degree supervisor | Iaccarino, Gianluca |
| Thesis advisor | Iaccarino, Gianluca |
| Thesis advisor | Mani, Ali, (Professor of mechanical engineering) |
| Thesis advisor | Pruitt, Beth |
| Degree committee member | Mani, Ali, (Professor of mechanical engineering) |
| Degree committee member | Pruitt, Beth |
| Associated with | Stanford University, Department of Mechanical Engineering. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Ohiremen Dibua. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Ohiremen L Dibua
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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