3M makes more than 50,000 products, but one technology is at the core of a wide range of products, including road signs, grinders, and overhead projectors.
One of 3M's most important secrets is a technology the company calls "microreplication." It involves covering large sheets of plastic or other surfaces with precisely-sculpted microscopic shapes, thousands of them per square inch, in unending uniformity.
"Imagine pyramids, even like Egyptian pyramids," said Ken Smith, a scientist in 3M's traffic safety division. "It's that kind of structure on a very small scale, all over a plastic film."
The pyramids, ridges and other shapes 3M produces alters the physical, chemical and optical properties of surfaces. A sheet of microscopic pyramids can make road signs brighter because of the way they reflect light, Smith said.
"Those kinds of structures are more efficient at returning the light from your headlights, right back to you as a driver in car," he said. "They return about two-thirds of the light that falls on them back towards the car."
The technology dates to the 1960s, when it was used to make inexpensive overhead projectors for schools and offices. But microreplication has spread across 3M's businesses. The company adapted the technology to improve the performance of everyday items from sandpaper and golf gloves to grinders and cell phones. The technology touches tens of thousands of 3M's products and is critical to the company's innovation, said Ernie Gundling, leadership consultant.
"It's one of 3M's core technology platforms," he said.
Gundling studied 3M for his book, The 3M Way to Innovation. Microreplication has given new life to old products, he said.
"They've been able to reinvent some of their oldest businesses, including the sandpaper business, as well as come up with very unique applications in new areas," he said.
3M guards its microreplication secrets closely.
One microreplication machine could fill a medium-size house and costs more than $1 million, according to 3M. However, no one outside the company, and even most 3M employees are allowed to see a microreplication machine. The machine melts plastic pellets and squeezes them into rolls of film.
A BRIGHTER DISPLAY
There's a good chance you see 3M's microreplication technology at work on your TV, cell phone or computer screen. The technology produces sheets of optical film that make those screens as much as three times brighter. The film improves energy efficiency in display screens, helping extend battery life in laptops, tablet computers and cell phones.
You'll find all manner of dismembered TVs in the lab of 3M researcher Dave Lamb. He spends a lot of time tearing down TVs that don't use 3M's film, and then puts 3M film on them.
"You can see the area where the film was applied is brighter than the area where the film is not applied," he said.
The image is brighter because the microscopic structures on the film's surface reflects light that would otherwise be directed toward the ceiling or floor instead toward where people will most likely watch the set.
But microreplication can also be used to modify something as solid as steel, and has revolutionized the abrasives business that got 3M started about a century ago.
Microreplication allowed 3M to develop abrasives with identical self-sharpening grains. They cut about five times as fast as traditional abrasives and last about seven times as long. They can quickly scour away steel and other metals.
And now microreplication is showing up in 3M's health care business.
Kris Hansen of 3M is working with drug companies on ways to use a patch to deliver vaccines and other drugs, quickly, painlessly and effectively with a skin patch that could replace hypodermic needles. The patch delivers medication or vaccination through tiny structures about 1/25th of an inch long.
"It's got about 1,300 little tiny microneedles on it," she said. "We put the drug or vaccine on the very tip of the microneedle and put that into the skin. And what the patient wears something that is about the size of the quarter and they wear it for maybe ten seconds, or ten minutes. And when they take it off the vaccine has been delivered into the skin."
3M is seeking regulatory approval for the patch. Hansen said the microneedles may soon deliver vaccines and some large selling drugs she can't name. It'll be another case of one half-century old idea, giving rise to yet another product.