From the New York Times this morning:
"Spencer Silver, a research chemist at 3M who inadvertently created the not-too-sticky adhesive that allows Post-it Notes to be removed from surfaces as easily as they adhere to them, died on Saturday at his home in St. Paul, Minn. He was 80."
The Times goes on:
"Since their introduction in 1980, Post-it Notes have become a ubiquitous office product, first in the form of little canary-yellow pads — billions of which are sold annually — and later also in different hues and sizes, some with much stickier adhesives. There are currently more than 3,000 Post-it Brand products globally.
"Dr. Silver worked in 3M’s central research laboratory developing adhesives. In 1968, he was trying to create one that was so strong it could be used in aircraft construction.
"He failed in that goal. But during his experimentation, he invented something entirely different: an adhesive that stuck to surfaces, but that could be easily peeled off and was reusable.
"It was a solution to a problem that did not appear to exist, but Dr. Silver was certain it was a breakthrough … He patented the adhesive (technically called acrylate copolymer microspheres) in 1972. But two more years passed before someone at 3M paid serious attention to it: Art Fry, a chemical engineer in the tape division lab, who was looking to develop new products."
And the rest is history.