Inks May Play Key Role in Smart Labels

By Sean Milmo, Ink World European Editor | 10.09.09

Smart labels and other similar ‘intelligent’ products using small chips or conductive polymer materials would appear to have little relevance to the general future of printing and inks.

The majority of smart labels comprise electronic components with the facility to store and transmit data. Since they do not have a visual function, they are regarded as being outside the realm of printing.

However, conventional and digital printing techniques are being used to produce smart labels, but it is in such small quantities that it is very much a niche business.

Possibilities for Ink

These applications are presenting the prospect of the use of printing and inks for the mass-scale manufacture of electronic data products which could transform the printing and ink sectors.

“As the technology develops, it will be possible to replace an increasing percentage of the electronic component (in these electronic devices), perhaps to the point where the integrated circuit as we know it will be replaced entirely with ink,” Dan Lawrence, manager of print as manufacture at Flint Ink, told a recent conference on smart labels at Churchill College, Cambridge University, England.

He noted that printing has the technical capability to manufacture electronic materials on a scale which would satisfy the requirements of a mass market for a new era of sophisticated but cheap electronic components.

“On the assumption of one square millimeter per electronic component, a single press could generate 140 billion components per hour or 45 million per second,” he said. “At 300 microns per side and 20 micron line widths, this equates to 1,500 billion components per hour.”

The printing industry is a long way from being geared up to make a massive expansion out of graphics into the manufacturing of electronics.

“Obviously your average jobbing printer is not able at the moment to convert his Heidelberg equipment to a printer for making electronic materials,” said Stuart Evans, chief executive, Plastic Logic Ltd., which is developing technologies for ink jet printing of plastic electronics.

“But it is not unimaginable that some of these printers with a fairly good clean room will be using the next generation of presses, made by Heidelberg and manufacturers of digital printing equipment, to print electronics,” he added.

Printing Electronics

The new business of printing electronics would not only revolutionize printing but also the electronic industry as well. Instead of microchips and integrated circuits being made in a few giant plants, as at present, they would be made in a multitude of printing works scattered across the globe.

“The manufacture of these electronics will be done in a pervasive way all around the world and not in a small number of $3 billion to $4 billion silicon chip plants,” Mr. Evans told the conference, organized by IDTechEx, Cambridge, England, a smart labels consultancy.

IDTechEx believes that the smart label market worldwide, primarily consisting of electronic article surveillance (EAS) and radio frequency identification (RFID), will be worth approximately $500 million this year. Smart inks or laminates and electronic laminars account for only 15 percent of total sales.

The main use of EAS is as an anti-theft device in the retail sector while RFID is employed mostly for the tracing and tracking of bulk loads through the supply chain.

Smart ink and laminates sales this year will amount to only $11 million, although IDTechEx estimates there are approximately 100 companies making intelligent inks.

A major market for smart inks is in diagnostic applications, such as devices for showing changes in temperature, pressure, light and humidity and for detecting the presence of viruses, bacteria and gases.

Andrew Jackson, applications marketing manager, Sherwood Technology, Nottingham, England, showed the conference a range of labels which change color when put through a sterilization or curing process. The labels deal with a major difficulty in hospitals caused by staff omitting to sterilize medical instruments and equipment.

Ford Motor Company asked Sherwood to provide a solution to a problem of polyurethane suspension parts missing a heat-curing process in the production line which was resulting in costly vehicle recalls.

“A self-adhesive circular ‘dot’ is now applied to each part prior to the curing process,” said Mr. Jackson. “These dots are initially pale pink but turn black after exposure to the curing temperature for the correct time. The customer has proven the reliability of the system in practice with the virtual elimination of non-cured parts leaving the factory.”

Sherwood has also introduced a range of intelligent labels for helping people prevent over-exposure to the sun. They are mainly small stickers which, when applied to the skin, will change color to indicate when a safe dose of sun for a specific skin-type has been reached.

Technical Challenges

However, makers of smart inks are complaining about technical barriers to further advancement of their products.

“It is not the inks themselves which are the problem but the printing of them,” Andrew Kesingland, technical sales manager at Luminescence, Harlow, England, told the conference. “The smarter the inks, the more difficult it is to print them. It is very difficult, for example, to print a heat-sensitive ink for use in low temperature because it has to be printed at room temperature.”

Furthermore, while smart inks are cheap at present compared with the expense of RFID or plastic electronics, the cost is only coming down slowly, according to IDTechEx. On the other hand, the costs of RFID and other electronic systems are declining rapidly.

Over the last 10 years, the average selling price of an RFID tag has plummeted from $100 to $1, and looks certain to drop to even lower levels where RFID systems will be competing with laminar electronics.

IDTechEx predicts that over the next eight years, sales of smart inks/laminates will more than double to $25 million. On the other hand, RFIS sales will rise more than twenty-fold to approximately $5 billion by 2010, while at the same time those of laminar electronics will go up 13 times to approximately $1 billion.

A major driving force behind this expansion will be the extension of electronic tracking and tracing systems from bulk loads to individual products. Already, U.S. retail chains are testing the use of RFID rather than bar-code systems to raise the efficiency of inventory audits and to speed up the flow of customers through check-out points.

“The big issue at the moment is the need to get the cost of RFID tags right down,” Peter Harrop, IDTechEx’s chairman, told the conference. “Wal-Mart is conducting RFID trials at a cost of $1 per tag but they would like to get the cost down to as low as 3 cents.”

A worldwide product tagging project is being organized through the Auto-ID Center, a research partnership between the Massachusetts Institute of Technology (MIT) and Cambridge University, which is being supported by consumer product companies like Unilever, Proctor & Gamble and Coca-Cola. It is also being backed by developers of new technologies in the field such as Flint Ink, Avery Dennison, NCR Corporation and Philips Semiconductors.

Auto-ID’s objective is to have 96-bit smart tags with an integrated circuit and antenna embedded in individual products. These will be able to be scanned by wireless radio-frequency readers so that their data can be transmitted to a network on the Internet.

“(This) technology will help businesses save billions of dollars in lost, stolen or wasted products,” said Helen Duce, associate director of Cambridge University’s Auto-ID Center. “Benefits to consumers will be equally dramatic.”

Auto-ID and other research teams involved in smart technologies believe that the cost of RFID and other electronic tags can soon be decreased to five cents through changes to the design of integrated circuits, antenna and manufacturing processes.

The biggest cost reduction will have to be in the making of integrated circuitry. The expense of assembling the integrated circuit with the antenna and other components and applying them to product packaging will also have to be considerably decreased.

Printing could in the long term play a big role in the slashing of costs, particularly in the final stages of the whole manufacturing process.

Already, RFID antenna are being placed on tags through conventional printing techniques. Soon inks could be developed containing many more of the components required for RFID and other electronic devices.

Instead of comprising pigments, binders, solvents and additives, these new inks would consist of nanoparticles of tubular, spherical and other shapes, polymers with conductive and light-emitting properties, molecules acting as solvents and additives, Mr. Lawrence told the conference.

“The inks can be printed by existing printing processes with each having advantages for certain applications,” said Mr. Lawrence. “It is likely that different processes will be used at different stages to ensure continuous manufacture.”

With its thick ink film, screen ink has, for example, an already proven technology in electronics. Litho is also suited to high viscosity applications. “Gravure needs a low viscosity but is able to handle very aggressive solvents which may be needed in these inks,” said Mr. Lawrence.

Inevitably there are a series of major technological obstacles which have to be tackled. These include the need to increase the performance of polymer semiconductors, the requirement for a substantial improvement in printing resolution and registration and the necessity for barrier coatings and a clean-room printing environment.

Once these hurdles are overcome,conventional printing is poised to become a manufacturing arm of the global electronics sector.