Category: Former Students

David Chang-Yen

David A. Chang-Yen was born in Trinidad , W. I. on August 30th1977 . He received his B.Sc. and M.Sc. degrees in biomedical engineering from Louisiana Tech University , Ruston , Louisiana in May 2000 and August 2002 respectively.  He completed his doctorate in Mechanical Engineering at the University of Utah in Salt Lake City , Utah in May 2005, and is currently a post-doctoral associate with the Utah State Center of Excellence for Biomedical Microfluidics. He is also one of the co-founders and current Vice President of Research and Development of Wasatch Microfluidics Inc., a Salt Lake City-based company dedicated to the field of microfluidic solutions for biotechnology applications. He is the author of six journal articles on polymeric-based sensors, nanotechnology, and microfluidic applications, and is the co-applicant on five related patents.

Project Work:  

David’s current research includes several distinct subjects:

  • Microscale Polymeric Optical Sensors
  •  Nanotechnology-Microsystem Integration
  •  Polymer Microfluidic Systems
  • Microfluidic Packaging
  • High-Density Microarray Fabrication
  • Multiphysics BioMEMS Design for Commercial Applications

Each of these aspects of his research contributed to his dissertation, culminating in the development of a multiphysics-based, multianalyte biosensor that is suitable for commercial-scale manufacturing. The initial applications intended for the sensor are blood constituent monitoring, including glucose and cholesterol, intended for point-of-care clinical use. Additionally, spin-off technologies such as a polymeric microfluidic spotter system for high-density array fabrication and robust microfluidic packaging have been developed and are being investigated for further commercial significance. The polymeric microfluidic spotter systemis currently being developed for commercial applications in the fields of high-throughput SPR and microassays by Wasatch Microfluidics Inc.

Masters Thesis: ELECTROSTATIC SELF-ASSEMBLY OF A RUTHENIUM- BASED OXYGEN SENSITIVE DYE USING POLYION-DYE INTERPOLYELECTROLYTE FORMATION

PhD Dissertation: Integrated Microsensor Design

Josh Eckman

Josh Eckman is pursuing a Master of Science in Mechanical Engineering with plans to graduate in May 2006.  He graduated Summa Cum Laude in Business Administration and Asian Studies from the University of Utah in 2004.   During his undergraduate career, he enrolled in a variety of math, physics and engineering courses in preparation for the graduate program.

Josh’s MS work involves the design and fabrication of a multi-layer microfluidic device for high throughput deposition and/or sensing of DNA, proteins, cells, sugars, lipids and other biomolecules.

Josh is one of the co-founders of Wasatch Microfluidics, Inc., a Salt Lake City-based company focused on the application of microfluidics to improve the capabilities of biomedical research.

Contact:  josheckman@hotmail.com

Mark Eddings

Mark A. Eddings was born and raised in Bountiful, Utah. He attended Bountiful High School where he graduated in 1997. After serving a two-year LDS mission to the Fiji Islands, he returned home and began studying Mechanical Engineering at the University of Utah. He graduated in May of 2004 with a Bachelor’s Degree in Mechanical Engineering and received his PhD in Bioengineering.

Research Work:

  • Development of a painless drug delivery system using microneedles. The project utilized photolithography, wet etching, electroplating, and other MEMS processes.
  • Development of micropumps for on-chip fluidic control for biosensors and protein spotting applications. Work was focused on PDMS-based peristaltic and permeation/diffusion pumps.
  • Development of highly arrayed continuous flow immunoassays in a microfluidic device.
  • Development of an ELISA assay for detection of antibodies to drug treatments given to Multiple Sclerosis (MS) patients.

James C. Stephenson

PhD Candidate Electrical and Computer Engineering

I began my work in micro fabrication in 1994 at the University of Utah as an undergraduate student.  We developed a thin-film integrated inductor/transformer process to be used in cell phone antenna impedance matching circuits.  Upon graduation I started working on magnetic memory contract for MicroMEM Inc. until December 2001.

In February 2002 I returned to the University of Utah to pursue a PhD in Electrical Engineering working on a micro scale Nuclear Magnetic Resonance Spectrometer.  Our system is intended for field use and is therefore portable and very low power.  We have developed a permanent magnet system capable of producing 2.3 Tesla magnetic field.  Additionally, we have improved upon existing micro-NMR probe technology by increasing the fill-factor to nearly 100%.

For further information please go to: http://www.eng.utah.edu/~jstephen

Tammy Ho

I am a bioengineering student at the University of Utah and am working on my undergraduate and graduate degree in a dual MS/BS program. I currently am working on a micro-fluidic lipid extraction device. This device centers around automating the Folch Extraction which is a process that extracts lipids from blood or plasma. The goal in automating this process is to provide a quick screening method for the Smith-Lemli-Opitz Syndrome (SLOS).

Project: Lipid Extraction from Whole Blood as part of SLOS Diagnostic Tool

Meregu Srinivas

I am currently working on the extension of Cyclical Electrical Field Flow Fraction (CEFFF). CEFFF is a separation technique in which particles are separated according to their electrophoretic mobilities. Cyclical fields are applied on typical Electric field Flow Fraction system (EFFF) systems instead of DC as electrode polarization causes 90% depletion in field in DC systems. Though, from theory it is understood that cyclical fields improve the field. It is still unknown what percentage of field is improved as typical EFFF systems consist of only two electrodes. In CEFFF at the critical frequency the elution time of the particles will be lowest. For frequencies higher or lower than this frequency elution time would be higher than the above mentioned critical frequency. If electrophoretic mobility is known and flow rate of the carrier solution is kept constant, then effective field can be estimated for that given characteristics of carrier solution. The effective field can also be measured if the system contains a reference electrode in addition to existing two electrodes. The goal of this project is to build an integrated electrode in CEFFF system for measuring the effective field and compare it with the estimated effective field from the model.

Theory developed previously on CEFFF is very simple and does not include many important issues Hence there is a need to develop a strong mathematical model which could include all the issues in CEFFF. The major issues in previously developed theory are:

  1. The band broadening and the particle interaction issues are not introduced in the previous model so there is need to modify a single particle model to a concentration based two dimensional model using numerical methods which would take into account all of the particles in the channel.
  2. The particle is assumed to start near one of the channel walls when the field is initiated to simplify the equations. But practically particles can exist anywhere inside the channel so it would be good to use probability theory rather than assuming particles start at one of the walls.

The final goal of the project is to characterize the polystyrene particles and various catalysts (obtained from Dr. Virkar). Based on CEFFF theory, when characteristics of carrier and field are kept constant, the elution time of particles for certain range of applied frequencies depends only on electrophoretic mobility. Hence after proper calibration of CEFFF system, electrophoretic mobility can be estimated from the elution time data.

Publications:

Journal Papers:

Merugu Srinivas and Bruce K. Gale , “Cyclical Electrical Field Flow Fractionation”, Electrophoresis, submitted.  (Likely publication date Feb 2005).

Invited Papers:

Bruce K Gale, Himanshu J Sant, Avinash Saldanha, Meregu Srinivas, Mahesh Thoppil, “Microfabricated Field Flow Fractionation Systems,” in Proc. of the Second Annual Louisiana Microsystems and Materials Conference, Baton Rouge, LA, August 20-22, 2001.

Reviewed Conference Papers:

Ameya S Kantak, Srinivas Merugu, Bruce K Gale, “Microfabricated Cyclical Electrical Field Flow Fractionation,” in Proc. of MicroTAS 2003, Squaw Valley, California, October 5-9, 2003.

Srinivas Merugu, Nithin Narayanan and Bruce K. Gale, “High Throughput Separations Using A Microfabricated Serial Electric SPLITT System,” in Proc. of MicroTAS 2003, Squaw Valley, California, October 5-9, 2003.

Conference Papers:

Ameya Kantak and Bruce K. Gale, “Microscale Cyclical Electrical Field Flow Fractionation,” in Proc. Of the 11th International Symposium on Field Flow Fractionation,Cleveland,OH,October 7-10, 2003.

Srinivas Merugu, Nithin Narayanan, and Bruce K. Gale, “Microscale Serial SPLITT Systems,” in Proc. Of the 11th International Symposium on Field Flow Fractionation,Cleveland,OH,October 7-10, 2003.

Meregu Srinivas and Bruce K. Gale, “Cyclical Electrical Field Flow Fractionation,” in Proc. Of the 10th International Symposium on Field Flow Fractionation,Amsterdam,Netherlands,July 2-5, 2002.

Master of Science Thesis

Cyclical Electrical Field Flow Fractionation