Dr. John D. Williams

Assistant Professor of Electrical and Computer Engineering

Associate Director of the Nano and Micro Devices Center

301 Sparkman Drive, Optics Bldg. 400n

Huntsville AL 35899

Phone: (256) 824-2898,    Email: john.williams@uah.edu

 

Office Hours:  Tues. and Thurs. 11 AM - 12 PM in EB 218

Team

Research

Publications

Teaching

Advising

NMDC

STEM

Pictures

Dr. Williams

Current Students

Graduates

Dr. John D. Williams

Assistant Professor of Electrical and Computer Engineering

Associate Director of the Nano and Micro Devices Center

University of Alabama in Huntsville

301 Sparkman Drive, OB 400n

Huntsville, AL 35899

Phone: (256) 824-2898

Fax: (256) 824-6618

Email: john.williams@uah.edu

 

 

Brief Biography

 

Dr. John D. Williams received his BS in Physics from the Louisiana State University (LSU) in 1996 where he examined the breakdown of low temperature aluminum superconducting Josephson junctions in low temperature superconductors. He then became a process and beamline technician at LSU's Center for Advanced Micro Devices (CAMD). At CAMD, he developed hands on experience with ultra high vacuum equipment, sputter deposition, ion milling, contact and deep X-ray lithography, wet and dry etching of silicon, scanning electron microscopy, and electroplating. In 1998, he joined the staff of the Cornell Nanofabrication Facility (CNF) as its first MEMS Exchange Engineer and worked to characterize and document CNF fabrication processes for the DARPA MEMS Exchange program. During his stint at CNF, Dr. Williams learned a great deal about Bosch and chorine inductively couple plasma etching, step and repeat lithography, various etch techniques, and chemical vapor deposition. He returned to LSU in 1999 to complete a Masters in Engineering Science on UV LIGA fabrication processes in 2001. Dr. Williams completed his PhD in Engineering Science from Louisiana State University in 2004 after developing a series of novel resist processes for high aspect ratio SU-8 microstructures using contact lithography and combining UV-LIGA processes to develop a micro-electromagnetic relay. In the summer of 2004, Dr. Williams moved to Sandia National Laboratories in Albuquerque, New Mexico where he was responsible for the science and technology development of LIGA microfabrication. At Sandia, Dr. Williams spearheaded the development of the tilted woodpile photonic crystal, and the lithographic patterning of transparent glass microstructures for the DARPA NGIMG project. During his 3.5 year tenure at SNL, Dr. Williams aided in the development of a dozen microfabricated devices, including THz waveguides, a handheld NMR, and the DARPA Nano Air Vehicle project. Dr. Williams left Sandia to join the Electrical and Computer Engineering faculty at UAHuntsville, in the spring of 2008. He is currently an assistant professor and Associate Director of the Nano Micro Devices Center. His interest include RF MEMS engineering, Bio inspired sensors, 3-D Photonics, and Glass MEMS.

 

Funding Support at UAH

Alabama EPSCoR GRSP

Alabama NSF EPSCoR Program

UAH Office of the Vice President for Research

National Science Foundation

Oblique Bio. Inc.

USASMDC/ARMSTRAT

 

 

 

 

 

 

 

Amanda Black - PhD Student

Amanda grew up in Coleman, Alabama and now works as a US Army civilian engineer in Huntsville.  Her research is focused on the design and implementation of a metastable Xe gas laser.  She holds a bachelors in Computer Science and will defend her MS thesis in EE with an Optics focus in August or September of 2013.

A. V. Bhavyabhushan Yadav - MS Student

Mr. Yadav received his B.E in Electronics & Communication Engineering from R.V.College of Engineering, Bangalore, India in 2010.  His research interests include bio-nanoelectronics, nanofabrication, and  micro/nanofluidics.

 

Current Research :   Fabrication of Lab On a Chip devices on photo-definable glass and Microlenses.

William Gaillard - PhD Student

Mr. Gaillard grew up in Jackson, Alabama before coming to UAH to major in Optical Engineering.  He has since earned a Masters in EE on optical spectroscopy using microfabricated cuvettes.  He is currently working on microfluidic reactors with in-plane spectroscopic analysis and real time feedback control.

 

Other interests include:  Programming and course instruction for Arduino STEM outreach program,  and 3-D rendering with Autodesk Maya/Blender.

Muhammad Shuja Khan - PhD Student

Mr. Khan received BS Electrical Engineering from the University of Engineering & Technology, Lahore, Pakistan and MS Electronic Engineering from Ghulam Ishaq Khan Institute of Engineering Sciences & Technology, Pakistan in 2007 and 2009 respectively. His research interests include BioNanotechnology, BioMEMS and nanodevices fabrication.

 

Currently, Mr. Khan's focus is to provide synthetic platform using nanodevice to engineer artificial biological membrane fused with different proteins.

Olusegun Sholiyi - PhD Student

Received his B.Eng. in Electrical Engineering from the University of Ilorin, Nigeria in 1992 and MSc in Microwave and Wireless Subsystems Design from University of Surrey, UK in 2008. Currently a PhD Student in Electrical and Computer Engineering Department, University of Alabama in Huntsville. Areas of research include:

➢ Micro-Machined coax phase shifters

➢ Phased-array antennas

➢ Microwave-passive components for Radar and satellite applications

➢ Electromagnetic modeling and computation

 

Carl Sanderson - MS Student

Carl received his Bachelors in Optical Engineering from UAH and is currently working on his Masters in Electrical Engineering. He is currently working on optical cell design and plasma applications for metastable Xe gas lasers. Carl is employed as a research assistant by the SMAP Center to the US Army SMDC Directed Energy Division.

`Emmanuel Bizanis - Undergraduate Student

Finite element analysis.

Halbach magnet design.

Simulation of electroosmotic pumping in microchannels.

STEM Outreach

DOCTORAL STUDENTS– 3 to date, in alphabetical order

 

1. Reza Kamali Sarvestani - High Quality Factor Microwave Resonators Using Embedded Structures in PCB,

    June 2011.  Instructor of Electrical Engineering at Rowan University from 2011- 2012.  Currently an

    Assistant Professor of Computer Science and Engineering at Utah Valley University in Orem, Utah.

 

2. Po Sun – Studies on Metallic Three-Dimensional Photonic Crystals, June 2012.  Post Doctoral Fellow

    under Wei-Chuan Shi in Computer and Electrical Engineering at the University of Houston.  Currently

    at Sunny Optotech North America in San Jose, California.

 

3. Khalid Hasan Tantawi, Porous Silicon Platform Technologies for Transmembrane Protein Investigation,

     June 2012.  Currently with the Mechantronics Program, at Motlow College, Tennessee.

 

MASTERS STUDENTS – 4 to date, in alphabetical order

 

1.  Nathan Bergquist - RF Engineering and Modeling of Rectangular Micro-Coax Phase Shifter, March 2011.

     Currently with the Alabama Technology Network in Coleman, AL.

 

3.  Randy Gaillard - Optical Analysis of Microfabricated Glass Cuvettes for Spectroscopic Applications, June

     2012.  Currently a PhD Student in Electrical Engineering, UAH

 

2. Jonathan Braun Hanks – Calibration of Fieldable Imaging Pryometer for use with Hydrocarbon Flames,

    March 2011.  Currently with Polaris Sensor Technologies, in Huntsville, AL

 

4. Jacqueline Andreozzi- Generation of Radio Frequency Inducted Metastable Xenon for Future

    Application as the Gain Medium in a Diode Pumped Rare Gas Laser System, July 2013.  Currently a PhD

    Student for Dr. Brian Pogue in Engineering Science at Dartmouth College.

 

UNDERGRADUATE STUDENTS

 

1.  Jason Kiem, BS Electrical Engineering, 2011

2.  Jake Helton, BS in Electrical Engineering, 2010 - Published Paper

3.  Janesckza Oates, BS in Electrical Engineering, 2009 - Published Paper

4.  David Hawthorne, BS in Electrical Engineering, 2009

 

  • Photonic Crystals

    Featured on the cover of the Journal of Micro/Nanolithography, MEMS and MOEMS in April 2010.

     

    This program investigates the electromagnetic design requirements for designing and applying three dimensional metallic photonic crystals.   To date, we have fabricated a tilted woodpile photonic crystal and modeled the propagation of electromagnetic wave through various different designs.  These design studies have resulted in a novel application for the tilted woodpile photonic crystal.  This research team has proposed that a photonic paint created by mixing large amounts of sub millimeter size photonic crystals into a transparent medium can be used to tag an object with a distinct infra-red signature.  Photonic paint, which is looks like brown dirt trapped in a transparent plastic coating, can be used to track an object in shipment, spy on an object from large distances using an infra-red laser, or act as an anti-counterfeit coating to protect valuable objects.  In the past, we have proposed and demonstrated the ability to manufacture photonic crystal media acceptable for this design using X-ray lithography.  However, new laser based optical lithography tools currently being developed will provide a commercially viable optical lithography process for manufacturing this paint in large scale within the next five years.  Our goal is to fabricate these crystals over large areas using single photon or 2- photon lithography  and  provide a unique tag and track technology for both commercial and military applications from near infra red to microwave frequencies.

     

     

     

     

     

     

     

     

     

     

     

     

    Figure 1.  (a) Slanted pore in PMMA. (b) Tilted woodpile of electroplated gold after PMMA removal.

     

    Figure 2. (a)  Complete bandgap demonstrated for tilted woodpile. (b) Measured passband in tilted woodpile with different beam cross sections.   All data taken using a hemispherical  directional reflectometer.

     

     

    Figure 3. Photonic Paint (a) imaginary refractive index of polyethylene in the IR showing each of the absorption peaks present. (b) FDTD simulation of the average percent reflectance of the tilted woodpile at any angle when suspended in a polyethylene mixture.

     

     

  • RF Ferrite Filters

    Microfabricated coaxial lines offer significant advantages over stripline conductors and conventional line feeds for modern lightweight electronics.  However their application is currently limited to electrical connections and waveguide resonators.  I propose to integrate this technology directly with ferrite and ferromagnetic materials for the development of phase shifters, isolators, and circulators that add true multi-functionality to the microfabricated coax radio frequency (RF) circuits. This proposal provides a clear method for direct implementation of reciprocal and nonreciprocal devices into the current 3-D MERFS concept.  Thus, the enhanced fabrication and design scheme allows for the production of complete RF systems on commercial microwave circuit board substrates. Applications for these devices include synthetic aperture radar (SAR) for small unmanned air vehicles (UAVs), atmospheric weather radar systems, GHz networked data transfer, satellite communications, and possibly cell phones.

     

    The governing factor for component assembly methods is determined by the end user application. For example, SARs developed for in-flight reconnaissance currently undergo a large number of design iterations requiring individual components to be purchased and assembled for the creation of the device.  In other applications, such as high power satellite transceivers, insertion losses, size, and mass already play a significant role. Tests are then performed and the device is optimized by altering these components. This is commonly achieved using COTS components that are classically machined and therefore limit the size and mass of this component to a few cubic inches and half a kilogram respectively.

     

    I propose a new microelectromechanical systems (MEMS) assembly technique that allows the production of multiple designs at once while dramatically reducing size, weight, cost, and power losses in the system simultaneously through the use of monolithic device integration and batch fabrication. To demonstrate the concept, I will develop a high frequency transmit/receive (TR) module using coaxial magnetic RF electronics manufactured by multilayer lithographic techniques. Operational performance characteristics of this design will be verified in an RF test chamber through collaborations between UAHuntsville and local research organizations such as Dynetics or the US ARMY AMRDEC lab. The TR module is the key component required for signal amplification and phase matching immediately prior to the antenna array in these applications.  These devices use ferrite phase shifters, isolators and circulators to adjust the amplitude of signals traveling to and from the antenna. Currently, TR modules are either assembled using low cost commercial off the shelf (COTS) components or manufactured subunits that are specifically designed for the target application. The prototype TR module itself will consist of an eight element phase shift array, magnetically driven isolators, LNA, PA, and a tunable antenna. This is the minimum number of TR elements required to demonstrate adequate beam steering capability for modern transmission sources. The device may also contain magnetic latching switches for generating true time delay over the spectral band. These elements provide a swath of the core technologies required to develop any advanced RF electronic system. Thus, the TR module is ideal for demonstrating the capability and application space for integrating micro-magnetic components directly into a MEMS coaxial circuit design. Miniaturization of these structures significantly reduces the size and weight of current radar and communication systems.

     

  • Passive RF Induction Filters

    Featured in the cover article of the November 2011 Microwave Journal,  Divine Innovation:10 Technologies Changing the Future of Passive and Control Components, by David Vye.

     

     

    We have developed a novel filter design that  uses both inductive and capacitive features to increase the resonator frequency into the 10s of GHz at quality factors over 300, while further reducing the size and allowing for a low cost batch fabrication procedure. The new resonator consists of a micro-solenoid fabricated using vias in a printed circuit board. One of the vias is separated into two single pieces using a small dielectric gap and provided two separate solenoid turns. An illustration of the new resonator is presented in figure 1 for the two turns resonator. Each of these new single solenoid turns receives a fraction of the inductance based on the location of the dielectric gap. While the turn to turn capacitance for each side remains high because of its parallel capacitive contribution to the adjacent turn from the nearby micro-solenoid. On the other hand by moving the dielectric gap along the via, the value of these new inductances and capacitances can be changed. As a result of that, the related pole-zero values in the equivalent impedance of the resonator are able to be changed. Pole-zero transfer was used to increase the performance of resonators in the previous applications. It is utilized to maximize the quality factor in the recent study.

     

    Analytic modeling of the circuit has been investigated using a π-circuit model for the poles and zeros location in the equivalent impedance of the circuit. Moving the dielectric gap along the inductor via transferred the dominant resonant pole far from the nearby poles and zeros. This provided the ability to optimize the resonant frequency and quality factor of the coil. Also electromagnetic simulations of the devices were performed with Ansoft-HFSS software. Results of the EM-simulation were compared directly with p models and showed negligible differences.

     

    Figure 1.  Schematic diagram and optical image of one turn resonator in Duroid substrate.

     

    The highest Q-factor in the designed model was fabricated. S-parameter measurements of the fabricated device were taken experimentally using a microwave probe station. Both the resonance frequency and quality factor have been extracted. Experimental data shows close agreement with modeling and simulation. This result applied to narrow band microwave filters provided high quality factor at giga Hertz frequencies. Low cost standard PCB fabrication techniques would also decrease the cost, and complexity of device commercialization when compared to other ON-Chip and OFF-Chip resonators, and MEMS structures.

     

    Resonators were realized using a 3.0 mm thick RT/Duroid 5880 low permittivity substrate with a 35 µm copper cladding on the surface. Vias were drilled and filled using commercial printed circuit board (PCB) fabrication processes. A drilling size of 125 µm radius was used to meet design specifications. The width of each conductor was 250 µm and the distance between two conductors made the pitch size 250 µm. The dielectric was introduced using KMPR photoresist and the top surface conductors were electroplated by copper.

     

    Fabricated resonators were measured using a HP8363 network analyzer and GSG Cascade Micro-tech probes. The short-open-load-thru (SOLT) calibration was completed using a Cascade Micro-tech impedance standard substrate (ISS). Deembeding of the ground loop pads surrounding the resonator in figure 2(g) was carried out after conversion of S-parameters to Y-parameters. Then the S-parameters were calculated using the new Y-parameters. Figure 3 illustrates the measured and simulated S21 of a fabricated resonator. It shows through both simulation and experiment that pole placement at 12.27 GHz and 12.25 GHz respectively, results in a high quality resonator.

     

    Extraction of the quality factor using S21 resulting maximum quality factor of 306 in the 12.25 GHz for a two turn solenoid. This is lower than the value of 480 which was made by the simulation. Fabrication error in the resonator structure associated with capacitor caused a shift in second pole and a lower quality factor. The result of this experiment shows that for a high quality factor not only should the poles be close to the imaginary axis but also they should be kept far from each other. This work presents a commercially manufacturable inductive resonator.

     

    Fabrication of such a narrow band microwave filter can increase the efficiency of the high frequency circuits. This resonator captures 10 mm2 of the printed circuit board. Compared to a ring resonator with 625 mm2 captured area for the same working frequency it is very small and it can be easily fabricated near the integrated circuits using standard PCB fabrication. While it has higher quality factor compared to EBG and LTCC model and silicon based resonators.

     

    Figure 2.  Measurement result and simulation data of a one turn solenoid resonators with a dielectric gap at z= 0.375 mm.

     

     

    Figure 3.  Dynamic simulation of the H-Field

     

    Figure 4.  Dynamic simulation of the E-Field

     

  • Photosensitive Glass

    Micropatterned glass offers a few very significant advantages over PDMS microchannels.  First, glass is inherently hydrophilic.  Second, glass silicate materials are compatible with strong acids and organic solvents.  Glass can also be used to over a wide temperature range (-80oC – 400oC).  Furthermore, glass can be thermal fusion bonded to produce hermetic seals between individual device layers.  Finally, glass materials are generally transparent between 400 nm and 3000 nm.  The problem with using glass for microfluidic channel development is that the surface roughness produced is almost always greater than 0.5 microns resulting in rough surfaces that inhibit reaction chemistry and eliminate transparency.

     

    The development of microfabricated glass structures that are optically smooth and transparent from every direction offers significant opportunities for chemical microreactors and the spectroscopic study of a wide range of microfluidic systems. To implement this concept using current technologies, one must investigate the material science and process engineering parameters required to create three dimensional glass structures using laser ablation or lithographic patterning followed by a post etch treatment that reduces sidewall roughness from approximately 1-3 μm to less than one tenth of the desired optical wavelength. Recent advances in glass microfabrication demonstrated by Williams have provided the ability to generate small glass structures with vertical sidewalls that are transparent to light between the wavelengths of 400 nm and 4 μm. These devices have a sidewall roughness less than 40 nm and can be patterned from 50 μm x 50 μm to 1 mm x 1 mm in size. An example of our current optical cell technology is presented in Figure 1. Furthermore, we have extended the process required to generate the structure to produce 3-D structures and hermetically sealed glass structures that are optically transparent along all three principle Cartesian axes. Using this preliminary information we now wish to understand the role of various glass properties on the melt dynamic so that we can learn how to anneal any size and shape of microstructure desired through the application of a systematic set of design parameters using the physical and chemical properties of the glass. We will apply this study to understand the design rules required to utilize this technology broadly for microfluidic reactors that require spectroscopic measurements to provide optimal feedback control of the chemical reaction within.

     

     

     

     

  • Porous Silicon Supported Biomembranes

    The long term goal of this effort is to understand the bio-electronic circuit behavior in complex membrane protein functional groups in an attempt to engineer complex biological processes across the boundaries of a cell or organelle on artificially engineered platforms.  To achieve this objective, one must study protein complexes in a highly quantifiable fashion.  The central hypothesis of this research effort is that small batch fabricated combinatorial arrays of protein fused lipid membranes can be used to advance the physical and chemical understanding of how lipid concentration and diffusion, cholesterol additives, secondary protein complexes and external environmental variables affect the performance of transmembrane proteins in biology.  The rationale behind this methodology is that the ability to pattern multiple different physiological samples and test them simultaneously on separate membranes provides a deterministic approach for understanding the requirements to fuse complex multi-protein functional groups onto one or two sides of a single membrane.  Thus, this effort will increase the fundamental knowledge of protein/membrane interactions and overcome the challenges required to assemble complex artificial cellular membranes and organelle structures.

     

    In order to test this hypothesis, we are batch fabricating membrane templates and structured membrane protein complexes.  During this effort, lipid bilayers fused with transmembrane proteins will be patterned onto one and later both sides of a thin porous silicon membrane and characterized using both metrological and electronic measurement techniques.  Over the next two years, Epithelial Sodium Channel protein (ENaC) and Bacteriorhodopsin will be individually evaluated using this template.   Both proteins are well understood transmembrane ion channels.  ENaC regulates the flux of Calcium ions across the membrane, and Bacteriorhodopsin acts as a proton pump across the membrane. Proteins fused to these bilayers will communicate through ion exchange mechanisms that can be directly measured using electrochemical impedance spectroscopy and Nernst I-V characteristics.

     

     

    The resulting effort will use multiple measurement techniques on this novel platform to provide a better understanding of the role of complex lipid structures in cell membranes and new methodologies for nanobiological fuel cells and bioelectronic circuits. This project addresses current research topics in the combined fields of materials engineering, electrical engineering and molecular biology.  As such, there are multiple approaches being examined for a wide number of different materials and application spaces.  However, our transformative approach to institute protein fused lipids and lipid double layers on small arrays of porous silicon advances the current understanding of interfacing silicon (and therefore the inherent coupling of thin film transistor technologies) with molecular biological functionality.  The expected outcome of this effort is improved understanding of lipid functionality though for parallel data sampling over what can amount to dozens or even hundreds of membrane structures at the same time.  This allows for quantitative analysis by means not previously achieved.

     

  • Prior Research Efforts

    The following Figures and captions are used to detail the successes Dr. Williams has had while focusing his efforts toward the development of new high aspect ratio MEMS processes.

     

     

     

     

     

     

     

     

    Figure 1. SU-8 exposed with contact lithography to produce 40:1 aspect ratio structures in 1 -1.5 mm of resist. Base for an electromagnetic relay comprised of 4 resist layer and metallization layers with a critical resist aspect ratio over 30:1. SU-8 resist process yields greater than 90% from run to run. Even structures with aspect ratios greater than 100:1 have been demonstrated using 5 um features in 600 um of resist. However at these sizes, diffraction of light was proven to distort the base of the pattern. Off axis exposure of this resist was used to generate a microfluidics mixer that operates in very short channel lengths.

     

     

     

     

     

     

     

     

     

     

    Figure 2. Using Deep –ray Lithography of PMMA, Dr. Williams has been able to generate high aspect ratio plastic and metallic microparts for a number of different applications including, but not limited to 3-D Photonic crystals in gold, 70:1 aspect ratio Ni THz filters, Gold plated Fabry Perot Gratings with 2 um surface error across a 4” wafer for THz sources, and 2-D magnetic photonic crystal structures using 45/55 NiFe. This is the first application of this electroplating bath to high aspect ratio structures. Other materials electroplated include permalloy, NiFeCo and highly corrosion resistant paramagnetic CuNi alloys.

     

     

     

     

     

     

     

     

     

    Figure 3. Other devices include optically smooth and hermetically sealed Foturan glass (DARPA NGIMG), and Bosch etched silicon MEMS. The second image is of a supersonic micro thruster under DARPA NAV lead to the first successful production of a 3 layer silicon fusion bond procedure at Sandia National Laboratories. Using simple magnetic engineering principles we demonstrated a through wafer design for micro NMR coils that significantly reduced the parasitic capacitance of these devices and fabricated a 0.9 Tesla permanent magnet with 10-5 T uniformity over the 0.0156 mm3 area required to operate the NMR.

Citation Summary:  JDW Google Scholar

 

Publications in Preparation or Under Review:

 

K.H. Tantawi, J. D. Williams, “Defects in Photosenstive Glass Process Technology,” under review.

O. Sholiyi, L. Chao, M. Afsar, J. Lee, Y, Hong, and  J. D. Williams, “Compatibility Analysis of SU8 Negative Photoresist with Barium Ferrite Powder,”  under review.

J. Andreozzi, A. Clark, K. Kendrick, J.D. Williams, “Optical Pumping of RF Generated Metastable States in Naturally Abundant Xenon,” under review.

 

Peer Reviewed Journal Publications:

 

M. S. Khan, N. S. Dosoky, J. D. Williams, “Engineering Lipid Bilayer Membranes for Protein Studies,” Int. J. Mol. Sci., vol. 14, pp. 21561-21597, 2013.

W. R. Gaillard, K. H. Tantawi,  V. Fedorov, E. Waddel, J. D. Williams, “In-plane Spectroscopy with Optical Fiber and Liquid Filled APEX Glass Microcuvettes,” J. Micromech. and MicroEng., vol. 23, 107001, 2013.

L. Chao, O. Sholiyi, M. N. Afsar, J. D. Williams, "Characterization of Micro-structured Ferrite Materials: Course and Fine Barium, and Photoresist Composites," IEEE Transactions on Magnetics, vol. 49, no. 7,  pp. 4319-4322, 2013.

K. H. Tantawi, E. Waddel, J. D. Williams, “Structural and Composition Analysis of Apex and Foturan Photodefinable Glasses,” J. Materials Science, vol. 48, no. 5, pp. 5316-5323, 2013.

K. H. Tantawi, B. Berdiev, R. Cerro, J. D. Williams, “Porous Silicon Membrane for Investigation of Transmembrane Proteins,” Superlattices and Microstructures, vol. 58, pp. 72-80, 2013.

K. H. Tantawi, R. Cerro, B. Berdiev, M. E. Diaz Martin, F. J Montez, J. D. Williams, “Investigation of Transmembrane Protein fused in Lipid Bilayer Membranes Supported on Porous Silicon,” J. Med. Eng. Tech., vol. 37, no. 1, pp. 28-34, 2013.

K. H. Tantawi, W. Gaillard, J. Helton, E. Waddell, S. Mirov, V. Fedorov, and J. D. Williams, “In-plane spectroscopy of microfluidic systems made in photosensitive glass,” Microsyst Technol, vol. 19, pp. 173-177, 2013.

P. Sun and J. D. Williams, “Metallic Spiral Three-Dimensional Photonic Crystal with a Full Band Gap at Optical Communication Wavelengths,” IEEE Photonics J., vol. 4, no. 4, pp. 1155–1162, Aug. 2012.

P. Sun and J. D. Williams, “Photonic Paint Developed with Metallic Three-Dimensional Photonic Crystals,” Materials, vol. 5, no. 7, pp. 1196–1205, Jul. 2012.

P. Sun and J. D. Williams, “Passband modes beyond waveguide cutoff in metallic tilted-woodpile photonic crystals,” Opt Express, vol. 19, no. 8, pp. 7373–7380, Mar. 2011.  UAHuntsville - OSE Best Paper Award, 2011.

K. H. M. Tantawi, J. Oates, R. Kamali-Sarvestani, N. Bergquist, and J. D. Williams, “Processing of photosensitive APEX™ glass structures with smooth and transparent sidewalls,” J. Micromech. Microeng., vol. 21, no. 1, p. 017001, Jan. 2011.

R. Kamali-Sarvestani and J. D. Williams, “Design and Fabrication of Monolithic High Quality Factor Rf-Solenoids Using Dielectric Substrate,” Microwave J, vol. 54, no. 11, pp. 76–90, 2011.

J. D. Williams, C. Schmidt, and D. Serkland, “Processing advances in transparent Foturan® MEMS,” Appl. Phys. A, vol. 99, no. 4, pp. 777–782, May 2010.

R. K. Sarvestani and J. D. Williams, “Frequency-Dependent Control of Grain Size in Electroplating Gold for Nanoscale Applications,” Electrochemical and Solid-State Letters, vol. 13, no. 6, pp. D37–D39, 2010.

J. D. Williams, “Fatigue and fracture mechanics aspects of LIGA fabricated nickel and Ni-20%Fe microstructures,” IJTAMM, vol. 1, no. 3, p. 266, 2010.

J. D. Williams, P. Sun, W. C. Sweatt, and A. R. Ellis, “Metallic-tilted woodpile photonic crystals in the midinfrared,” J. Micro/Nanolith. MEMS MOEMS, vol. 9, no. 2, p. 023011, 2010.  Cover Article

X. G. Peralta, M. C. Wanke, C. L. Arrington, J. D. Williams, I. Brener, A. Strikwerda, R. D. Averitt, W. J. Padilla, E. Smirnova, A. J. Taylor, others, “Large-area metamaterials on thin membranes for multilayer and curved applications at terahertz and higher frequencies,” Appl Phys Lett, vol. 94, no. 16, pp. 161113–161113, 2009.

J. D. Williams, R. Yang, and W. Wang, “Numerical simulation and test of a UV-LIGA-fabricated electromagnetic micro-relay for power applications,” Sensors and Actuators A: Physical, vol. 120, no. 1, pp. 154–162, 2005.

J. D. Williams and W. Wang, “Microfabrication of an electromagnetic power relay using SU-8 based UV-LIGA technology,” Microsyst Technol, vol. 10, no. 10, pp. 699–705, Dec. 2004.

R. Yang, J. D. Williams, and W. Wang, “A rapid micro-mixer/reactor based on arrays of spatially impinging micro-jets,” J. Micromech. Microeng., vol. 14, no. 10, pp. 1345–1351, Jul. 2004.

J. D. Williams and W. Wang, “Study on the postbaking process and the effects on UV lithography of high aspect ratio SU-8 microstructures,” J. Micro/Nanolith. MEMS MOEMS, vol. 3, no. 4, pp. 563–568, 2004.

J. D. Williams and W. Wang, “Using megasonic development of SU-8 to yield ultra-high aspect ratio microstructures with UV lithography,” Microsyst Technol, vol. 10, no. 10, pp. 694–698, 2004.

W. Wu, J. Williams, and P. W. Adams, “Zeeman splitting of the coulomb anomaly: A tunneling study in two dimensions,” Phys. Rev. Lett., vol. 77, no. 6, pp. 1139–1142, 1996.

 

Patents and Pending Patent Applications:

 

L. Larka, J. D. Williams, R. Gaillard, “Oligo Synthesis Micro-reactor,” Preliminary Patent Application, Sept. 2013.

J. D. Williams, R. G. Lindquist, “Systems and Methods for Tuning Resonators,” Preliminary Patent Application, Oct. 2013.

J. D. Williams, R. Kamali-Sarvestani, “High Quality Factor Resonator,” US Patent Application, filed Oct. 30, 2011.

X.G. Peralta, I. Brener, J. O’Hara, A. Azad, E. Smirnova, R. D. Averitt, J. D. Williams, “Terahertz Metamaterials,” U.S. patent application filed  October 31, 2008.

J. D. Williams, W. Sweatt, “Method to Fabricate a Tilted Logpile Photonic Crystal,” US Patent No. US 7,820,365 B1, Oct. 26, 2010.

W. Sweatt, J. D. Williams, “Laser Remote Sensing of Backscattered Light from a Target Sample,” US Patent No. US 7,336,351 B1, Feb. 26, 2008.

 

Peer Reviewed Conference Publications:

 

R. Kamali-Sarvestanti, J. D. Williams, “Fabrication of High Quality Factor RF-Solenoids Using Via Structures,” IEEE Wireless and Microwave Technology Conference, Clearwater FL. (April 2011).

R. Kamali-Sarvestanti, J. D. Williams, “New High Quality Factor Solenoid Based Tuned Resonator,” IEEE International Microwave Symposium, Baltimore, MD. (June 2011).

R. Kamali S., J. D. Williams, “Fabrication of High Quality Factor RF-Resonator Using Embedded Inductor and Via Capacitor,” Conference of the IEEE Industrial Electronic Society (IECON) Phoenix, AZ. (Nov. 2010). Top 10 Student Paper Award - 1400 Attendees

J. Namkung, Y. Zou, R. Kamali, J D. Williams, R. G. Lindquist, “Improvement of sensing characteristics by using microelectroplating technique for nematic liquid crystals based chemical and biological sensors,” CLEO, San Diego, CA, (May 2010).

R. Kamali S., J. D. Williams, “Application of Pulse Frequency to Control the Nano Grain Size of Gold Plated Thin Films,” ICCE-17, Honolulu, HI. (2009).

G. Papadopoulos, J. Tyll, A. Drake, R.Chue, J. D. Williams, P. C. Galambos, “Air Entrainment Studies for a Supersonic Micro Ejector System,” ASME Fluids Engineering Conference, Jacksonville FL. FEDSM2008-55220 (2008).

X. G. Peralta, C. L. Arrington, M. C. Wanke, I. Brener, J. D. Williams, E. Smirnova, A. J. Taylor, J. F. O’hara, A. Strikwerda, R. D. Averitt, W. J. Padilla, "Flexible, Large-Area Metamaterials Fabricated on Thin Silicon Nitride Membranes," in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest (CD) (Optical Society of America, 2008), paper CFY4.

X. Peralta, C. L. Arrington, J.D. Williams, A. Strikwerda, R. D. Averitt, W. J. Padilla, J. F. O’Hara, I. Brener, “Terahertz metamaterials on Thin Silicon Nitride Membranes,” MRS Spring Meeting # 1077-L07-18 (2008).

 

Other Conference Proceedings:

 

K. H. Tantawi, R. Cerro, B. Berdiev, J. D. Williams, “Investigation on Transmembrane Ion Channels Suspended Over Porous Silicon Membranes,” Proc. of Biotech 2013, Washington DC (May 2013).

W. R. Gaillard, J. D. Williams, “Photosensitive Glass Processing for Microfluidic Applications,” HARMNST, Berlin, Germany (April 2013).

P. Sun, J. D. Williams, “Studies on Metallic-Tilted Woodpile Photonic Crystals,” Frontiers in Optics 2011/ Laser Science XXVII, San Jose, Ca. (Oct. 2011).

R. Kamali S., J. D. Williams, “Pulse Plating Effects on Nano Grain Size of Gold Films,” Alabama Composites Conference, Birmingham, AL (Aug. 2010).

K. H. M. Tantawi, J. D. Williams, “The Biology Age: Electricity from Proteins,” Alabama Composites Conference, Birmingham, AL (Aug. 2010).

K. H. M. Tantawi, J. Oates, J. D. Williams, “Processing of lithographically defined Apex glass structures with smooth and transparent sidewalls,” 6th International Conference and Exhibition on Device Packaging, Scottsdale, AZ, (March 2010).

J. Williams, et.al, “LIGA Fabricated Photonic Crystals for the Mid-IR,”   PECS VII 2007.

J.D. Williams, C. Arrington, W. C. Sweatt, D. W. Peters, I. El-Kady, A. R. Ellis, J. Verley, F.B. McCormick, “Tilted logpile photonic crystals using the LIGA technique,” Proc. SPIE 6289, p. 62890A (2006).

Schmidt CF, Sweatt WC, El-Kady I, F.B. McCormick, D.W. Peters, S.H. Kravitz, J.C. Verley, U. Krishnamoorthy, D. Ingersoll, W.G. Yelton, G. Subramamia, J.D. Williams, “New Infrared photonic lattice coating,” Proc. SPIE 6289, p. 628916 (2006).

F. B. McCormick, J. G. Fleming, S. Mani, M. R. Tuck, J. D. Williams, C. L. Arrington,H. Kravitz, C. Schmidt, G. Subramania, J. C. Verley, A. R. Ellis, I. El-kady, D. W. Peters, M. Watts, W. C. Sweatt, J. J. Hudgens, “Fabrication and Characterization of Large-Area 3-D Photonic Crystals,” 2006 IEEE Aerospace Conference, VOLS 1-9 :1820-1827 (2006).

El-Kady et.al, “Photonic Crystals: From Nanosize Scientific Novelty to Realizable Applications,” International Conference on Nanotechnology, Egypt, 2005.

J.A. Palmer, J. D. Williams, T. Lemp, T. M. Lehecka, Francisco Medina, R. B. Wicker, “Advancing Three-Dimensional MEMS by Complementary Laser Micromanufacturing,” Proc. SPIE 6109, p. 61090A (2006).

R. Liu, X. Wang, Z. Zhou, and J. D. Williams, “Microneedles Array for Fluid Extraction and Drug Delivery,” IEEE International Symposium on Micromechanics and Human Science, p. 239-244 (2003).

J. Williams and W. Wang, “UV Lithography process for ultra high aspect ratio SU-8 microstructures with and without megasonic development,” High Aspect Ratio Micro Structures Technology Workshop (HARMST) 2003.

J. Williams and W. Wang, “Microfabrication of an Electromagnetic Power Micro-Relay Using SU-8 Based UV-LIGA Technology” High Aspect Ratio Micro Structures Technology Workshop (HARMST) 2003.

Courses Taught:

 

ECE 101:                     Introduction to Electrical, Computer, and Optical Engineering

EE   307:                     Electricity and Magnetism

EE /OPE 451:            Introduction to Laser Systems

EE/OPE 453:             Optoelectronics

EE 410/510:               Microfabrication and Semiconductor Process Engineering

EE 410/510:               Nanoscience and Engineering

EE 410/510:               Electromechanical Systems

EE 630:                       Adv. Math Methods in Electrical Eng.  II  (Class Notes and Assignments)

Phys/OSE/EE 645:  Lasers 1

 

Summer 2013:  EE 307:  Electricity and Magnetism

 

Fall 2013:              EE 307:  Electricity and Magnetism

                                        EE/OPE 453: Optoelectronics

 

Spring 2014:       EE 308:  Electromagnetic Waves

                                         EE 410/510:  Motor Design (Electromechanical Systems)

 

 

Undergraduate Teaching Philosophy:

 

I view my role as an undergraduate instructor to provide a clear and comprehensive view of engineering fundamentals to each and every student in the classroom.  I do this by pushing students to perform as much as possible and then backing off just enough to watch them excel.  I understand that skills vary significantly from person to person; however each and every student that matriculates through our program must be able to understand and demonstrate the basic tenets of the assigned curriculum.  I constantly adapt  techniques to maintain the attention of  every student in the classroom.  Attendees of my classes should expect to be called on to answer questions during every lecture.

 

I strongly emphasize the importance of writing notes, reading ahead of time, and doing homework without foreknowledge of the solution.  My homework problems are almost always theoretical, because I wish to emphasize to students that the ability to derive an answer is a far better skill than simply looking up an equation and plugging in an answer.  My tests generally come from textbook examples and homework problems.  They are however, theoretical and very comprehensive.  To aid students in the developmental challenge of theoretical problem solving, I make myself available in person from 9 AM-5 PM Monday through Friday and answer questions by email until 9 PM seven nights a week.  My mantra for student interaction is to put the student first at all times.

 

 

Philosophy and Methodology for Graduate Curricula:

 

The role of graduate student education is far different than that of undergraduates. Graduate students represent the top 10% of all engineering students in a university environment.  To be accepted into the program, students should have already demonstrated the basic tenets of the field they wish to study.  As such, they are now capable of in depth learning on each and every topic they choose to investigate within the field.  Thus, my goal as a professor is to provide a comprehensive understanding of the topic taught.  Students are expected to learn in class and independently using both required and alternative reading sources.  I generally expect a graduate student to go beyond what I am teaching in class.  However, I understand that most entering graduate students aren’t yet prepared for this challenge.  I therefore provide lists of other resources and routinely question students on ideas currently being published in the field that apply to the lecture in attempt to bring them up to the desired level of scholastic study.  I also require written reports that cite recent peer reviewed journals for each graduate level class.  All graduate students make individual project presentations in every class I teach except for the Engineering Math Methods course where I provide challenge problems that often exceed the difficulty level of the required textbook.

Graduate Student Advising:

 

I am a member of the graduate faculty in three academic programs:

 

Electrical Engineering

Optical Science and Engineering

Materials Science and Engineering

 

As a graduate student mentor, I am a strong believer in teamwork and equality within the group.  I typically spend 1-2 hours with each graduate student per week to provide clear and comprehensive direction.  Thesis based masters level students are expected to complete at least 8 courses (24 hours), write a thesis, and publish a peer reviewed article prior to graduation.  Doctoral students will complete 48 hours of graduate coursework,  teach undergraduates or develop K-12 STEM efforts for at least one year, and publish no less than 4  peer reviewed articles on their research prior to graduation.

 

Publicity Links:

 

Science Daily - Khalid Tantawi's graduate student experience.

 

 

Undergraduate Advising:

 

I am a student advisor for Electrical and Optical Engineering.  I take the role seriously and provide as much time as needed to develop successful plans for every student advisee.  As part of these discussions, I offer advice on study habits and course loads based on individual student needs.   I am a firm believer that student development occurs as much outside the classroom as it does within.  As such, I remind all students of other educational opportunities such as IEEE, the Society of Women Engineers, the Huntsville Electro Optical Society (HEOS) and student employment within the department. My goal is to encourage students do develop a vested interest in their careers and the success of the department.  The more they put into their college experience, the more they will take away.

 

I have also taken interested undergraduates on to perform independent research.  Some have worked in the laboratory and learned a great deal of process and/or electrical engineering.  Others have provided unique advances to my research program which have lead to two peer reviewed journal and one conference publication.  I take my role as an undergraduate research mentor very seriously.  Students receive hands on advice from me and spend a great deal of time being mentored one-on-one with the graduate student responsible for that research effort

 

 

Nano and Micro Devices Center

 

My primary service  role at UAH has been to facilitate activities in the Nano and Micro Devices Center (NMDC), a sub-component of the Center for Applied Optics (CAO).   There are currently twelve UAH professors that have a vested interest in NMDC operations:  3 from Mechanical Engineering, 2 from Chemistry, 1 from Physics, 4 from Electrical and Computer Engineering, and 2 from Chemical and Materials Engineering.

 

In November 2011, the NMDC became a working user center with hourly usage fees and corporate collaborations on  research grants.  There are approximately 20 graduate students and 2 undergraduate students using the facility during any given semester. NMDC professors have published no less than 20 journal articles, multiple conference papers, and have worked with the Office of Technology Commercialization to patent research coming out of the center during each of the past three years.  Furthermore, the center has aided in the success and graduation of no less than 10 graduate students since 2010.  The NMDC has also been host to six local companies and the US ARMY SMDC that perform research either as a user or through a research contract.  These corporate relationships have also led to 4 equipment donations.  The center receives $125,000 in state funds each year and is on track to take in more than $80,000 in user fees for its second strait year.

Competitive Robotics with Arduino :

 

Oak Park Middle School is leading the way forward with a new advanced robotics effort for the 6th-8th grade Talented and Gifted (TAG) program.  All of it made possible through a recent collaboration with our research group and Dr. Robin Gillespie of Oak Park.  Dr. Williams and his graduate students developed a series of lessons and activities designed to introduce microcontroller driven robots using a C based programming language and student assembled electronic circuits.

 

Students explored general concepts in robotics such as the physics of a DC motor and how solar energy can be harnessed to power electronics.   They were  introduced to an Arduino electronic controller package that is used to program and control an ATMEGA328 microcontroller.   The class of 21 students was then tasked to write programs that control light emitting diodes (LEDs), light dependent resistors (LDRs), DC motors, servos, and various sensor and actuator mechanisms using the Arduino electronics board.  Each student demonstrated a basic understanding of the assembly and programing of DC motor driven robots with active sensing and control mechanisms.

 

Publicity Links to STEM Outreach Efforts:

Decatur Daily - Arduino robotics

Decatur Daily - Recycled raft race including cardboard boats

Decatur City Schools Website - Oak Park's UAH robotics

UAH News -  Assistant Professor's STEM Outreach

 

Course Lectures for Arduino Robotics