David A. Horsley (Advisor)

Research Advised by Professor David A. Horsley

DAH3: Single-Crystal PMN Bimorph Deformable Mirrors

Hyunkyu Park

This project is focused on characterizing and modeling MEMS deformable mirrors for adaptive optics. We are interested in improving both the design and control of these mirrors as well as in developing new characterization and wavefront sensing methods. Although this project is presently targeted towards the vision science applications of adaptive optics, we are also interested in other applications requiring high-speed correction.

Project end date: 08/20/09

DAH5: Bioassay Based on Magnetic Recording Technology

Mei-Lin Chan

This project aims to develop a magnetic scanning probe microscope based on a magnetic tunnel junction (MTJ) sensor for the detection of magnetically-labeled biomolecules. Paramagnetic particles are employed as markers and incorporated with commercial DNA microarray technology to produce magnetically labeled DNA microarrays. An external magnetic tunnel junction is mechanically scanned across these arrays to detect and map out the localized magnetic fields from these particles. This new approach offers the potential to image centimeter-scale arrays of thousands of DNA spots while still...

BPN351: MEMS-Based Magnetic Probe Microscopy

Gerardo Jaramillo

A scanning-probe magnetic microscopy based on a high resolution magnetic tunnel junction (MTJ) sensor is under construction. MTJ sensors are highly sensitive magnetic field sensors but suffer from large 1/f noise. We have developed a new approach for reducing the 1/f noise in an MTJ sensor by using a MEMS resonator to mechanically modulate the magnetic field signal to a high frequency. MEMS actuators are uniquely suited to achieve both precise, micron-scale control of the average sample-to-sensor separation and to AC modulate the separation and MTJ signal at a very high frequency (...

BPN522: Formation of Optical Nanostructures Using Diblock Copolymers

Joanne C. Lo

Nanoscale plasmonic structures are at the forefront of innovations in biomolecular and chemical detection, nanoscale lithography, optical computing, and photovoltaic conversion. This project will focus on the design, fabrication, and operation of plasmonic structures. Fabrication will include an appropriate mix of top-down (e.g. nanoimprint lithography) and bottom-up (e.g. block copolymers) methods. Low-cost, batch-fabrication methods will serve as the foundation of this research.

Project end date: 02/03/10

BPN419: Board-to-Board Optical Interconnect: Lens Alignment System Incorporating Ultrasonic Stepper Motors

Brian Yoxall

An array of free-space optical interconnects composed of vertical cavity surface emitting lasers (VCSELs), alignment lenses, and photodiodes can alleviate communication limitation between boards in computer servers by replacing traditional copper wire connections. Actively controlled alignment lenses can be used to correct optical misalignment due to vibration loads, temperature fluctuation, and initial static offsets. A silicon micro-machined lens stage has been designed and fabricated to interface between linear piezoelectric ultrasonic stepper motors (USM) and an alignment lens...

BPN357: Parametrically-Amplified MEMS Magnetometer

Matthew J. Thompson

The focus of this project is on developing parametric MEMS resonators for application to gyroscopes, magnetometers, and RF MEMS filters. Optical parametric oscillators and microwave parametric amplifiers are widely utilized but their current MEMS counterparts are largely an academic curiosity. Parametric MEMS resonators have a number of advantages over the current state-of-the-art in MEMS resonator technology. First, they allow direct mechanical amplification of the sensor input, reducing the requirement for electronic amplification and allowing a corresponding reduction in power...

BPN602: Ion Channel Sensors Based on Mesoporous Silica Films

Pauline J. Chang

The goal of this project is to develop bio/chemical sensors based on ion channel proteins. Past efforts to develop similar sensors have been hampered by the complexities of providing both fluidic and electrical access to the ion channels. Here, mesoporous silica, a novel nanostructured material with ordered columnar nanopores, will be used to provide a fluid-porous support for ion channels inserted in a synthetic lipid membrane. Collecting the picoampere-level ion currents requires that the mesoporous layer provides low parasitic capacitance and that the silica-lipid membrane...

BPN605: Thin Film MEMS Pressure Sensor for Detection of Pressure Fluctuations in a Rat Brain due to Blast Injury

David G. Bonner

Explosion or blast injuries account for the largest number of injuries sustained in the Iraq and Afghanistan wars. For non-penetrating brain injuries, there is a lack of concrete scientific knowledge to explain how kinetic energy from a blast transfers into pressure transients in the brain. Animal model studies of the effects of traumatic brain injuries in rats are currently being conducted. A thin film MEMS pressure sensor has been modified for implantation into a rat brain, and is able to sense dynamic pressure waves a rat is exposed to in a blast. Additionally, the sensor is able...

BPN537: Liquid Bearing Micromotors

Brian Yoxall
Mei-Lin Chan

This project aims to develop a free, untethered micro-rotary platform based on liquid bearing support. The liquid bearing is essentially a small volume of fluid confined between the rotor and stator by patterned Teflon surface coatings. These bearings have the distinct advantage of being minimally affected by wear and capable of supporting both static and shock loads with reduced mechanical vibrations. The rotor is actuated through three phase electrostatic driving by etching notches in the perimeter of the silicon rotor and depositing metal electrodes onto the glass stator substrate...

BPN538: Lipid Membrane Biosensors

Christopher E. Korman
Mischa Megens

The lipid bilayer membrane is crucial to the proper functioning of biological processes. It not only secludes a cell's contents from the surrounding environment, but the membrane itself also serves as a dynamic scaffold for membrane proteins. The lipid membrane's thickness is of nanoscale dimension, thus making it an ideal structure for nano and micro bioengineering applications. Lipid membranes facilitate highly selective control and transport of molecules and ions entering and leaving a cell. As a result, they have great potential for use in applications such as drug screening and...