Small, square-shaped marks resembling a checkerboard, matrix symbols are capable of storing as much as 100 times the information as a barcode -- and in the same amount of space. Photo: NASA-Marshall

Think of them as barcodes with an attitude.

They're permanent, scannable, sometimes invisible, and they're popping up on items from vitamins to computer chips. They're matrix symbols, first studied for use by NASA in 1987 to help in tracking Space Shuttle components.

"In the space program, we have to track millions and millions of parts -- even tiny electrical components no larger than a dime -- to be certain of the integrity of critical systems," said Fred Schramm of NASA's Marshall Space Flight Center in Huntsville, Ala. "We need to know where each part was made, who touches it along the way and when and where it is installed."

This led NASA to study the matrix symbol -- technology that takes parts identification to the next level.

At the beginning of the Shuttle program, NASA tracked parts manually. "As the flight rate increased, we were gathering as much information as several large grocery stores each day," said Schramm, manager for engineering application projects for Marshall's Technology Transfer Department. "That created a backlog of paperwork that took as long as three months to catch up with the finished product."

In the mid-1980s, NASA turned to the barcode system, saving millions of dollars annually through automatic data entry.

"Barcode labels, however, didn't work well on some parts, especially ones that were small," Schramm said. "And a sticky label isn't going to last long on a Shuttle heat tile during the return to Earth. We had to find something that performed like a barcode but would remain readable for the part's full life cycle."

Enter the matrix symbol, capable of storing as much as 100 times the information as a barcode -- and in the same amount of space. The symbol is a small, square-shaped mark resembling a checkerboard. Unlike a barcode, which is scanned using a laser beam, the symbol is captured by a charged-coupled device (CCD), a solid-state chip that turns light into electric signals.

Matrix symbols were first studied for use by NASA in 1987 to help in tracking Space Shuttle components. In 1997, NASA's Marshall Space Flight Center moved to introduce the permanent marking aspect of this technology into the commercial sector. Today, the symbols can be found on items from mouthwash to mustard. Photo: NASA-Marshall

In 1997, the Marshall Center moved to introduce the permanent marking aspect of this technology into the commercial sector. Marshall formed an alliance with the developer of the "Data Matrix" symbol CiMatrix, a Canton, Mass., firm, and its parent company Robotic Vision Systems, Inc. (RVSI), to develop commercial applications for NASA's marking technologies.

"The applications for Data Matrix are unlimited," said Don Roxby, director of CiMatrix's Symbology Research Center. "Our staff has applied readable symbols on more than 80 different materials, including metal, plastics, glass, paper, fabric and ceramics. We have a method for successfully marking almost any substance or item."

The symbols have begun appearing on items used every day, said Roxby. "Because of their versatility, Data Matrix symbols are on a wide variety of products -- household items like Colman's English Mustard, Mennen Speedstick, Wyeth-Ayerst vitamins and Kodak film."

The technology has become the method of choice for direct-part marking in the automotive, health, semi-conductor, aircraft and electronics industries, he said.

"Before this technology was available, computer chip manufacturers had no way of marking their products, and counterfeit and stolen chips flooded the market," Roxby said. "The same is true with other small electronic parts. With Data Matrix, companies can place permanent marks on their components -- an obstacle to thieves and counterfeiters."

But it doesn't stop there, said Schramm. NASA has part identification needs that go beyond marks that can be seen.

Markings might be covered by paint, cork, foam or other protective coatings. Patents are pending for six methods of reading the symbols under coatings, through containers or within an assembly. NASA is currently soliciting partners to develop hand-held devices for reading these "invisible" markings. Interested companies should contact the Marshall Technology Transfer Department.

"This identification process will have untold implications for industry, as well as NASA," Schramm said. "New marking methods -- possibly ready this year -- should open the door to marking parts that must operate under extreme pressure, in some cases, thousands of pounds per square inch."