Read-write heads feel benefits of green tea

Derived in part from green tea, a new biodegradable machining compound for computer hard drive manufacturing is three to four times more effective than toxic counterparts.

Derived in part from green tea, a new biodegradable machining compound for computer hard drive manufacturing is said to be three to four times more effective than toxic counterparts. In an industry where more than 161 million hard drives leave assembly lines each year, the new compound could significantly improve manufacturing efficiency and minimise environmental risks.

Engineered by John Lombardi of Ventana Research Corporation in Tucson, Arizona, as part of a US National Science Foundation (NSF) Small Business Innovation Research (SBIR) grant, the chemical is part of a slurry that polishes the ceramics-made from aluminium oxide and titanium carbide-used in computer hard drive read-write heads.

“The potential merits of this compound are impressive,” said James Rudd, the NSF program officer who oversees Ventana’s award. “If confirmed in industrial settings, the three- to four-fold increase in efficiency could mean substantial reductions in hard- drive manufacturing costs, and all with a product that is less corrosive and more environmentally sound.”

The new compound is part of a family of machining fluids that bind to polishing debris and rapidly remove tiny particles from the polishing surface. The fluids are critical because imperfections in read-write heads must be less than 10 angstroms high. Larger defects can cause the head to crash into the disk, causing data loss.

Ventana formulates its fluid using a combination of synthetic proteins derived from common commercial chemicals and compounds extracted from green tea and other plants. Compared to many natural machining fluid compounds, which are often rare and expensive, the plant chemicals in the Ventana fluid are abundant and easily extractable.

Those chemicals give the Ventana fluid its ability to bind to the particle debris formed while polishing read-write heads.

According to Lombardi, the fluid’s possible biocompatibility and high affinity for ceramics and metals may lead to applications in wastewater treatment, where the compound could remove heavy metal contaminants from water, and medicine, where the compound may have advantages for delivering certain cancer treatments.