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Modeling And Feedback Control Of A Mems Electrostatic Actuator, Jason Edwards
Modeling And Feedback Control Of A Mems Electrostatic Actuator, Jason Edwards
ETD Archive
This thesis describes the mathematical modeling and closed-loop voltage control of a MEMS electrostatic actuator. The control goal is to extend the travel range of the actuator beyond the open-loop pull-in limit of one third of the initial gap. Three controller designs are presented to reach the control goal. The first controller design utilizes a regular fourth order Active Disturbance Rejection Controller (ADRC) and is able to achieve 97 of the maximum travel range. The second design also uses a fourth order ADRC, while additional modeling information is included in an Extended State Observer (ESO), which is part of the …
The Development Of An In Vivo Spinal Fusion Monitor Using Microelectromechanical (Mems) Technology To Create Implantable Microsensors, Lisa Anne Ferrara
The Development Of An In Vivo Spinal Fusion Monitor Using Microelectromechanical (Mems) Technology To Create Implantable Microsensors, Lisa Anne Ferrara
ETD Archive
Surgical fusion of the spine is a conventional approach, and often last alternative, to the correction of a degenerative painful spinal segment. The procedure involves the surgical removal of the intervertebral disc at the problematic site, and the placement of a bone graft that is commonly harvested from the patients iliac crest and placed within the discectomized space. The surrounding bone is expected to incorporate and remodel into the bone graft to eventually provide an immobilized site. Spinal instrumentation often accompanies the bone graft to provide further immobility to the targeted site, thus augmenting the fusion process. However, the status …
Mems (Micro-Electro-Mechanical-Systems) Based Microfluidic Platforms For Magnetic Cell Separation, Pulak Nath
Mems (Micro-Electro-Mechanical-Systems) Based Microfluidic Platforms For Magnetic Cell Separation, Pulak Nath
ETD Archive
Microfluidic platforms for magnetic cell separation were developed and investigated for isolation of magnetic particles and magnetically tagged cells from a fluidic sample. Two types of magnetic separation platforms were considered: an Isodynamic Open Gradient Magnetic Sorter (OGMS) and a multistage bio-ferrograph. Miniaturized magnets were designed using magnetostatic simulation software, microfluidic channels were fabricated using microfabrication technology and magnetic separation was investigated using video microscopy and digital image processing. The isodynamic OGMS consisted of an external magnetic circuit and a microfabricated channel (biochip) with embedded magnetic elements. The biochip is placed inside the magnetic field of the external circuit to …