Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coffee, Tea or Polishing Slurry?

27.04.2004


The same stuff that stains your coffee mug could reduce pollution in the computer hard-drive industry, while saving drive makers millions of dollars in manufacturing costs.


Two UA engineering grads and a UA engineering professor have developed an environmentally friendly polishing/lapping slurry that could save millions for computer hard-drive manufacturers. They are (from left) Materials Science and Engineering (MSE) alum Don Zipperian (Pace Technologies), MSE alum John Lombardi (Ventana Research Corp.) and MSE Professor Srini Raghavan. (Photo by Erica von Koerber, Evon Photography)


This separatory funnel contains an additive for polishing/lapping slurries that was developed by Ventana Research Corp. The additive is derived from green tea. (Photo by Erica von Koerber, Evon Photography)



The compound is derived from the tannin phytochemicals commonly found in plants. Green tea has a lot of them.

John Lombardi, president of Tucson-based Ventana Research Corp. combined phytochemicals from green-tea extract, synthetic proteins and an abrasive to produce a lapping slurry that is three to four times faster at polishing magneto-resistive heads than the ones currently in use. An added bonus — one that could save millions of dollars for hard-drive manufacturers — is that it’s also environmentally friendly, unlike many of the solvent-based slurries now used.


Lombardi, who earned his master’s (1994) and Ph.D. (1996) degrees from UA in Materials Science and Engineering (MSE), admitted that green tea isn’t intuitively obvious as a key ingredient in lapping slurries. He made the link after looking at the compounds that allow barnacles to cling tenaciously to ship hulls. These compounds have a chemical structure that is similar to that found in tannin phytochemicals. "This led me to start looking at various tannin phytochemical compounds as a general class of chemicals," he said.

"There are probably thousands of these chemicals in nature," Lombardi added. "We’re using green tea because it has a high percentage of phytochemicals."

UA MSE Professor Srini Raghavan has been working with Lombardi to test the green-tea compound as a slurry additive and is conducting basic science experiments to find out why it works so well.

A third team member, Don Zipperian, of Pace Technologies, is providing the industry perspective by determining precisely which slurry attributes are most valuable to hard-drive manufacturers. He also will be heavily involved in marketing the Ventana slurry. Pace Technologies is a Tucson-based company that sells products for micro-surface finishing.

The ceramic debris particles scrubbed away during hard-drive head polishing are submicron-size (less than a millionth of a meter in diameter) and cling to the surface, making them difficult to remove. Tannin phytochemicals have a strong affinity for these tiny particles, tightly bind to them and give them an electrostatic charge, which causes the particles to be repelled from other particles and the head surface. This makes them float so they can be easily washed away with water.

"The tannin phytochemicals play a dual role by increasing the polishing rate and enhancing the removal of particles produced by the polishing process," Raghavan explained.

Lombardi noted that the computer industry produces more than 161 million hard drives annually, with read-write heads that must have no imperfections larger than 10 angstroms. That’s tiny. The average human hair has a diameter of about 75,000 angstroms.

Polishing with this kind of precision isn’t easy. Zipperian, who earned his Ph.D. from UA MSE in 1987, compared the polishing process to flying a 747 at full throttle a few inches off the ground. Zipperian is chief technical officer for Pace Technologies, whose customers include semiconductor, hard-drive, and fiber-optics manufacturers, as well as companies in the metallographic industry that test materials, including metals, ceramics and plastics.

He said hard-drive manufactures incur significant disposal costs from the industrial solvents currently used for polishing read-write heads.

"As far as we know, all the chemicals we’re using should be biodegradable," Lombardi added. "Most of the chemicals and reactants we use are shipped in foil-lined bags and there are no materials-handling problems involved." Switching to these biodegradable chemicals could save manufacturers millions of dollars in disposal costs.

Ventana Research Corp. formulates specialty compounds, and now is looking at other applications for tannin phytochemicals. Their high affinity for metals and ceramics could lead to applications in mining, cancer treatment, high performance adhesives, specialty coatings, removal of metal contaminants from water, and wastewater treatment.

Lombardi, Raghavan and Zipperian developed the lapping/polishing slurries through a National Science Foundation (NSF) Small Business Innovation Research (SBIR) grant.

Ed Stiles | University of Arizona
Further information:
http://uanews.org/cgi-bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=9109

More articles from Process Engineering:

nachricht New technology for ultra-smooth polymer films
28.06.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Quantum material is promising 'ion conductor' for research, new technologies

17.08.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>