New Adhesive Handles Heat

It's one of baseball's most embarrassing moments: You had a great swing but the bat flew out of your hands.

Many baseball players coat their bat handles with sticky pine tar to prevent that from happening. Of course, you then drop the bat in the dust and it gets pretty cruddy.

Some French scientists have a better idea: They're developing a coating that's sticky when you touch it, but let go and it quickly hardens into a Teflon-like coating that repels dust.

Call it a "switchable adhesive," inventor Guillaume de Crevoisier of the French chemical company Elf Atochem writes in Friday's edition of the journal Science. For chemists, the term is temperature-sensitive "fluorinated polymer coating."

It's still experimental. But University of Massachusetts engineer Thomas Russell, who reviewed the French work, said the polymer is unique because it switches between sticky and slick merely when subjected to body temperature.

"There's lots of reasons why something of this nature could actually be used," Russell said, suggesting the baseball bats. "Or think of a Band-Aid. You want it to be sticky when it's on you," but not to stick to the trash can when you throw it away.

Adhesives and the hunt for more flexible ones are big business, Russell notes, pointing to sales of Post-It notes.

De Crevoisier combined a Teflon-like material with a stickier chemical. At room temperature, this crystalline polymer is solid, slick even.

But grab it, allowing the polymer to rise to body temperature, and the chemicals essentially melt a little, becoming sticky.

There's no reason the polymer couldn't be fine-tuned to adjust at other temperatures, de Crevoisier concludes in Science, suggesting everything from golf club coatings to industrial applications.