Welcome to my technical design portfolio.
Here you will find projects I've worked on at jobs and in classes. A lot of what I've done is proprietary, so unfortunately can't be shown or even mentioned here.

Single Use Mixing Systems
Sartorius Stedim, Bohemia, NY

Monoclonal antibodies (mAbs) are proteins that bind to and inactivate specific targets. They are produced naturally by our immune system but can also be engineered for use as drugs for many diseases including immune disorders and cancer. At pharmaceutical companies, big batches of antibody-producing cells are grown in large tanks (imagine the tanks at your local brew-pub for an idea of scale). Avoiding carryover from one batch of cells to the next is critical, so the tanks are either cleaned with harsh chemicals and steam, or are lined with single-use bags. Sartorius sells a wide variety of these bags: some for growing cells and others for general processes like storage or mixing.
At Sartorius, I led an international project team to investigate the next generation of single-use mixing. This inolved single-use bags, stainless steel tanks for supporting the bags, and electromechanical equipment for inducing the actual mixing. It was a great chance (and challenge) to manage the project, do some mechanical design, coordinate system integration, and also perform laboratory testing to assess mixing capabilities.

High Throughput In Vitro Diagnostic Instruments
Siemens Healthcare Diagnostics, Tarrytown, NY

Hospitals and testing companies, like Quest or LabCorp, use large central labs for processing samples as quickly and efficiently as possible. Some tests are performed manually, but many are automated, being run on high-throughput diagnostic instruments. These large labs have instruments linked together by a track. Test tubes move around the track, stopping at each module as needed-- as determined by their barcodes-- where a portion of the sample is removed and subjected to various diagnostic tests, for example: pregnancy, cardiac disease markers, presence of drugs of abuse, etc.
For part of my time at Siemens, I worked on a new immunoassay module of a larger modular system. I led mechanical design of a consumables handling subsystem and later led a team developing covers for the module. The Siemens website has more about the Atellica system.
For these high-throughput instruments, up-time is critical to the customers (operators and patients alike), so reliability of each subsystem within an instrument is extremely important. For the Advia Centaur XPT system, a second generation of an existing product, I led the mechanical redesign of a subassembly to eliminate the most common (though still rare) failure modes of the previous generation product. The small team started with a root cause analysis, continued with accelerated cycle testing to verify the root causes, then implemented design changes, and finally repeated accelerated testing to confirm that the changes were effective.

Point of Care Flu Test Device
Gaithersburg, MD

As the lead mechanical designer for this point-of-care device, I started with a proof-of-concept prototype, redesigned it, then refined it throughout its development cycle. The result is a compact, robust instrument that is easy to assemble and simple to use.
This instrument detected the first case of H1N1 Swine Flu during its clinical trials in April 2009!
For more information on the swine flu detection, please read the CDC's Morbidity and Mortality Weekly Report.

Gaithersburg, MD

I helped advance the design of a biothreat detector by designing various subsystems and performing system integration testing during its prototype-stage development. One review of an early generation of the product can be found here.

Manufacturing Process Improvement
GeneMachines, San Carlos CA (2002-2003)

As a Manufacturing Engineer, I was tasked with bringing these older products up to current manufacturing standards. These products became easier and faster to assemble due to my redesigning and outsourcing of parts, and overhauling Bills of Materials. With the creation of assembly documentation and testing protocols, the manufacturing department became less dependent on the historical knowledge of the technicians, allowing for greater flexibility within the manufacturing team.


Used for growing bacterial colonies
in microtiter plates

Transfers bacterial colonies from agar plates to individual wells of microtiter plates

Coordination of Manufacturing Transitions
GeneMachines, San Carlos CA (2002-2003)

I facilitated the transition of the "PolyPlex II" DNA synthesizer and "OmniGrid 300" large-scale microarrayer into Manufacturing. I planned and coordinated the creation of all of the assembly documentation including Bills of Materials, assembly instructions, and test protocols.

PolyPlex II

Synthesizes single-stranded DNA

OmniGrid 300
Places tiny spots of DNA onto microscope slides which are then used in gene expression analysis

OmniGrid 100 Microarrayer Improvement
GeneMachines, San Carlos CA (2002)

I lead a team to provide several key improvements to this product. I coordinated the work of five engineers on a variety of tasks including specifying and validating a new vacuum pump, redesigning the wash and dry stations to eliminate clogging and improve ease of cleaning, and testing and integrating a new plate-handling robot.

OmniGrid 100
Places tiny spots of DNA onto microscope slides
which are then used in gene expression analysis

Automated Optical Filter Changer
GeneMachines, San Carlos CA (2001)

For an enhancement to a colony-picking robot, I created a filter changing system to allow detection of bacterial colonies tagged with up to four fluorescent colors. I designed a simple motor controller and driver, along with the associated hardware. The solution minimally impacts the surrounding components, so can easily be sold as an option or an upgrade.

OmniGrid Accent Microarrayer
GeneMachines, San Carlos CA (2000-2001)

My team finalized the design of a low-cost microarrayer by transforming consultants' initial prototype into a manufacturable product. My design changes and leadership helped ensure a successful transition from the beta program to TUV/CE approval, into manufacturing production and throughout the project wrap-up.

OmniGrid Accent

Places tiny spots of DNA onto microscope slides
which are then used in gene expression analysis

Car-Sharing Prototype
ME 218d: Smart Product Design Projects, Stanford University (1999)

Our team of three designed, assembled, and tested an in-vehicle system and base station to demonstrate feasibility of a car-sharing concept. The in-vehicle system controlled car door and ignition access, and recorded mileage, time, and fuel gauge readings, yet required minimal vehicle modifications. After every trip, the system downloaded pertinent information to the base station via RF communication. This design proved that car-sharing could be cost-effectively implemented and helped realize the goals of San Francisco City CarShare.

In-Vehicle System
Our electronics recorded the car's statistics, controlled access to door locks and ignition,
and sent this information to the base station.

Base Station
The small electrical box provided all the communications that were necessary. The
laptop was used only to display status reports.

Giant "Simon Says"
ME 218c: Smart Product Design Practice, Stanford University (1999)

Our team's giant Simon Says game challenged users' reaction times while our "Score Accessories"-- a variable speed beanie and inflatable hat (not shown)-- proudly displayed the users' level of skill.

Simon Says
Users react by pressing the large colored panels with their hands and feet.

Speedy Beanie
A controller in this vest allowed a user's score to be displayed by the speed of the beanie.

Golf-Playing Robot
ME 218b: Smart Product Design Applications, Stanford University (1999)

In this team challenge, our autonomous robot successfully sensed IR beacons, tape boundaries, and bumps from other robots. It smoothly maneuvered around a playing field and accurately shot golf balls into goals.

High-End Bike Light
Light & Motion Industries, Monterey, CA. (1997)

To finalize a prototype design and manufacture the first run of this bicycle light, I designed and cut injection molds for various plastic parts including cable over-molding, and designed the bike attachment pieces. The Apex Lighting System was ready in time for its product launch at the Interbike trade show.

Ice Cream Maker
ME 103: Manufacturing and Design, Stanford University (1997)

This innovative ice cream maker's barrel holds ice and salt inside to allow ice cream mix to freeze on the outside. As the barrel is rotated, the ice cream crystallizes until the layer is thick enough to get scraped off into the extra trough. Protruding parts pack inside the product for easy storage. Fabrication focused on turned parts but also included milled and bent pieces.