tribo-, trib- (Greek: friction, rub, rubbing, grind, wear away; spend, waste time; be busy).

On Thursday, January 21, 1999, the following information came from Dr. Jacqueline Krim, Professor of Physics at North Carolina State University, Raleigh, North Carolina:

"Thank you for your inquiry. Yes, I coined the term nanotribology in a paper I wrote in 1991, entitled, 'Nanotribology of a Kr [krypton] monolayer: A Quartz Crystal Microbalance Study of Atomic-Scale Friction', J. Krim, D. Solina and R. Chiarello, PRL, 66, (1991) p. 181-184."

"I would define nanotribology as the sub-field of tribology involving contact geometries which are well-characterized at atomic length or time scales. These tend to be on the order of nanometers and nanoseconds."

"J. Krim"

Here are excerpts of other definitions of nanotribology:

Micro/nanotribology as a field is concerned with experimental and theoretical investigations of processes ranging from atomic and molecular scales to the microscale, occurring during adhesion, friction, wear, and thin-film lubrication at sliding surfaces.

This involves determination of the chemical, physical and mechanical properties of the surfaces undergoing relative motion at length scales of the order of nanometers. Interaction between rubbing surfaces occurs at asperities [roughness of surfaces] at which the local pressure and temperatures can be very high.

These conditions can lead to formation of tribochemical films with the unusual properties necessary for efficient wear protection. The nanomechanical properties of these films are being investigated by interfacial force microscopy (IFM) which is capable of determining the elastic constants and anelastic behavior of the films in boundary layer lubrication.

Tribology is the study of friction, lubrication and wear. Nanotribology is roughly defined as the study of these same phenomena down to the nN and nanometer force and length scales.

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Frictional electricity … was supposedly known to the ancient Greeks, particularly Thales of Miletus, who observed about 600 B.C. that when amber was rubbed, it would attract small bits of matter. The term "frictional electricity" gave way to "triboelectricity," although since "tribo" means "to rub," the newer term does little to change the concept.

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Lubrication is central to machine performance, but it's only part of the story. More and more, the bigger picture of machine health has been going by the label "tribology" [trigh BAH loh gee] which is based on the Greek word for "rubbing.", "grinding", or "wearing away", etc.

Tribology combines issues of lubrication, friction, and wear into a complex framework for designing, maintaining, and trouble-shooting the whole machine world.

Tribology is already providing data that could be used to produce transmission fluids that give automobile drivers better fuel economy and a smoother ride.

The most visionary tribology advocates and practitioners tend to view their field as the cure for much of what ails industry and even entire economies.

Tribology has evolved into a bona fide field of research and technology since 1966, when a group of industrialists in England coined the term with assistance from an editor of the Oxford English Dictionary.

The O. E. D. defines tribology as, "The branch of science and technology concerned with interacting surfaces in relative motion and with associated matters (as friction, wear, lubrication, and the design of bearings). " In 1968, H.P. Jost, in the February 8, 1968, issue of the New Scientist states, "After consultation with the English Dictionary Department of the Oxford University Press, we chose the term 'tribology'."

Many tribologists devote themselves to uncovering the fundamental chemical and physical dramas that underlie good and bad lubrication, friction, and wear. They are relying on new tools like friction-force microscopes, that can examine surfaces down to the molecular level (nanotribology?).

Transmissions are just one place where tribology makes a difference in the automotive industry. Other items on the agenda include controlling brake noise and wear, reducing internal friction in engines, and increasing the productivity, part quality, and energy efficiency of production machinery.

The "tribology tribe" points proudly to its crucial role in the thirty-billion dollar-a-year data-storage industry. When it comes to surfaces in motion, this is an especially harrowing arena. Yet it's through tribological know-how that makers of hard-disk drives have been able to squeeze more and more data into less and less space.

The head that reads and writes information to and from a hard disk flies about 50 to 100 nanometers above the disk surface. That's about one-thousandth the width of a human hair. Meanwhile, the disk typically spins beneath the head at about ten to twenty meters per second.

Woody Monroy, head of corporate communications for Seagate Technology, which makes disk drives, says that in terms of speed and clearance, it's the equivalent of an F-16 jet fighter plane flying one-sixty second of an inch [less than one millimeter] above the ground, counting blades of grass as it goes, at Mach 813 (or 813 times the speed of sound).

There are many reasons computers go down, but one of the most dreaded is when the head assembly literally crashes into the spinning disk's surface, tearing up and destroying precious data.

It's a tribological triumph that, despite all the hazards, vulnerabilities, and abuse by users, most storage systems operate fine most of the time because of proper coatings. The first protective layer is at most twenty nanometers thick. One leading-edge tribo-tactic is to fiddle with the molecular structure of the thin lubrication layer on top of the disk (nanotribology?).

Tribologists have plenty of challenges to keep them busy, but it's all part of making disk drives and economies run smoothly.

"Better Ways to Grease Industry's Wheels," by Ivan Amato
(Fortune, September 28, 1998).

"The Roman tribulum was a sledge consisting of a wooden block studded with sharp pieces of flint or iron teeth. It was used to bring force and pressure against wheat in grinding out grain. The machine suggested the way trouble grinds people down and oppresses them, tribulations becoming another word for troubles and afflictions. The word is first recorded in English in 1330."

Encyclopedia of Word and Phrase Origins by Robert Hendrickson
(New York: Facts On File, Inc., 1997), p. 680.