Researchers Develop Piano Keys of Synthetic Ivory That Feel Real : Science: Ban on use of elephant tusks prompted hunt for a substitute. New material’s advantage is that its surface resembles that of ivory, making it easier to grip than plastic.

To Henry Scarton, the solution to the problem of the piano keys was at his fingertips all along.

“My fundamental approach is to understand the physics of what’s going on, and this is physics,” he said, watching the ratcheting effect as he rubbed a thumb and forefinger slowly back and forth.

Scarton, an expert in the mechanics of vibrations and sounds--not to mention biomechanics and physiology, led a team of seven fellow scientists at Rensselaer Polytechnic Institute in a quest for synthetic ivory for piano keys.

The New York City piano manufacturer Steinway & Sons funded the $250,000 study, along with the state-run Northeast Manufacturing Technology Center, starting in the late 1980s. The scientists’ work began about the time a worldwide ban was going into effect on the sale or import of ivory, to protect endangered elephants from whose tusks it comes.

As early as the 1960s, piano makers were running short of ivory, and plastic had become the material of choice for keys on all but the most expensive instruments, according to Donald Dillon, executive director of the Piano Manufacturers Assn. in Dallas.

But ivory keys have an advantage over plastic ones. Because it is bony matter, ivory is pockmarked at random with holes and tiny fissures. Like the tread on a tire, that porous texture provides traction for the fingertips.

“When you’re at Avery Fisher Hall . . . and you’ve got on a tuxedo and the lights are on and you’re doing a Mozart concerto, you’re sweating,” Scarton said. “You also have oils on your hands. What happens is the finger will hydroplane, like a tire that hydroplanes when you go into a skid on a wet surface.”

Scarton and the other lead RPI researcher, Sal Calabrese, assembled experts in areas ranging from synthetic materials to tribology--the study of lubrication, friction and wear.

In 2 1/2 months, the team came up with the concept, Scarton said. Then came three years of fiddling with the materials to mass-produce the synthetic ivory, called RPIvory.

The latest procedure calls for the faux ivory to be hardened in nickel molds. A water-soluble powder--polyethylene glycol, a form of antifreeze--is mixed with the polyester solution and white dye to make the polymer resemble the color of keys.

Once the mold hardens it is immersed in water and the polyethylene glycol washes away. The places where the particles dissolve become the irregular pits and holes that simulate the porosity of ivory, Scarton said.

The team received a patent last year for RPIvory.

Steinway has tried out the synthetic ivory on a few grand pianos and plans to put it on five other Steinway grands, said Daniel Koenig, the company’s vice president of manufacturing. A discerning and demanding bunch, pianists didn’t know what to say when told that the keys were an ivory substitute, Koenig said.

“There is no doubt that it (RPIvory) has the touch and feel of ivory,” Koenig said. “But from our viewpoint, for a commercial venture the jury is still out by a long shot on whether anyone would pay the slight extra cost” for the artificial ivory instead of the now-standard plastic.

Under Steinway’s deal with the RPI research team, the piano maker has exclusive rights to the synthetic ivory’s use on piano keys. Scarton said he is weighing proposals for other commercial uses of the substance, such as on computer keyboards or the steering wheels of automobiles.

Other piano makers have been hunting for ivory substitutes too, according to Frank Seta, vice president of the Cincinnati-based Baldwin Piano Co. Baldwin has worked for years with General Electric’s plastics division, he said.

“All of us are trying to find a product that will give us those positive effects of ivory but address the negatives,” he said.

Ivory, he pointed out, was not perfect either. In addition to the supply problems, it tends to become brittle and to yellow as it ages.

But, undeniably, there is something about ivory that cannot be replaced by any plastic, polyester, ceramic or resin substitute, he said.

“There’s a mystique to it,” Seta said. “When you hear the word ‘ivory,’ what do you think of? Something like a diamond or gold. Very expensive material. It’s quality.”

Gary Busch, an associate professor at the Crane School of Music at the State University of New York at Potsdam, estimated that 90% of Americans playing pianos would not know or care they weren’t playing on ivory keys.

But for the other 10%, the piano aficionados or professionals, the allure of ivory remains strong, he said.

“It has to do with romance,” he said. “When you are playing on ivory, you’re playing the music of the past on the material of the past. Plastic is OK. Most pianos are made with plastic keys, and all musicians have pretty much adapted. But ivory is luxury.”