Background
My role as an industrial researcher comprised scientific and engineering projects that were fundamental to advancement of technology for new products. Often this included solving problems that caused shipping delays and field failures. The duration of these projects was from several weeks to several years. For each project, I would identify experts within the company and in academia. Then I would lead the team of engineers, technicians, temporary hires, post docs, and university students. I obtained corporate funding for several students through their PhD program in the Chemical Engineering Department at Carnegie Mellon University. Larger projects required me to identify and purchase capital equipment for specialized measurements such as rheometers, ellipsometers, and spectrometers. In some cases, I designed the layout of new chemical laboratory facilities for the project.
In one recent project, I was collaborating with a colleague who is a renowned expert in finite element modeling to interpret apparently anomalous friction test results. He discovered a new and unexpected phenomenon that could account for the results, but then he left the company before the model could be validated. I attended the training classes on finite element modeling, and continued the modeling. For modeling the airflow under the cellular pocket structure of the disk polishing tape, the deformation of the the soft elastomeric pad was needed to calculate the inlet flow. I developed the elastic solid model for the polishing pad and tape assembly loaded on the spinning disk.
In a related project, I employed the multiphysics package to model and design a lab test device for reactive gas injection into the disk boundary layer during polishing. Later when I transferred to another division within the company, I learned ANSYS and rebuilt the polishing pad model for a different polishing pad geometry. The completed projects below are documented in my publications, conference presentations, and patents.
Completed Project Menu
Materials Development
I carried out numerous materials development projects. For example early electrophotographic toner print quality was improved by adjusting the melt relaxation time with styrene/divinylbenzene gel. Organic glass forming monomers were evaluated as potential carriers for color ink jet printing. Early nylon 3D printing materials were found to solidify by crystallization. Low temperature rheological measurements were done to estimate lubricant response time scales at ambient temperature with time-temperature superposition. Self releasing photoresist formulation and flexible mold were developed for patterned media replication in recording disk manufacturing.
Surface Engineering and Nano-Mechanics
These projects include: engineering of surface nanomechanical properties, and surface chemical composition; surface cleaning and smoothing to sub nanometer roughness by abrasive tape and vapor phase chemical mechanical surface polishing; surface chemical modification to prevent contamination; nanomachining and contact mechanics of sub nanometer features.
Motor Grease and Oil Formulation Chemistry
Included in the completed projects list below are: advanced grease formulation for high speed ball bearing disk drive spindle motors; and low volatility, low viscosity, thermally stable, conductive oil for fluid bearing disk drive spindle motors.
My Formulation Chemistry Presentation at the ACS National Meeting in San Francisco, April 2017
Structural and Flow Modeling
I performed finite element modeling to help understand the magnetic recording disk polishing process. This involved structural modeling of the elastic soft pad loaded onto 25 mil thick Mylar tape and loaded onto the spinning disk. Material deformations were computed to provide the bounding surfaces for modeling the air flow between the tape and disk. With a flat tape surface, the air lift pressure partially offsets the load force which decreases the polishing friction force.
In another example, I carried out air flow modeling with the multiphysics simulation. This model was employed to design an ozone injector system. The ozone was injected into the boundary layer upstream of the polishing region on a spinning magnetic recording disk. The ozone facilitates vapor phase chemical mechanical polishing for ultrasmooth carbon overcoats by favoring conversion of tiny debris particles to gaseous carbon dioxide.
Lab Automation and Data Processing
I built automated lab test equipment and developed software for offline lab test data analysis. In one example I built a prototype magnetic recording disk polishing friction tester. I developed a user-friendly GUI for data acquisition and control. The tester emulated the full range of conditions in the manufacturing process, providing a window into the effect of polishing variables on product yield. Manufacturing version of the friction tester based on my prototype were constructed by a vendor and deployed in worldwide manufacturing and development.
In another case I constructed an apparatus with a user-friendly GUI to measure the (submonolayer) adsorbed water film thickness on carbon overcoated magnetic recording disks. The relative humidity could be varied between 0 and 90% and temperature from ambient to 70 C.
Many of the completed projects or work in progress were presented by myself or my coworkers at professional society conferences. A number of these presentation files are included in the link below.