A Market Test For New Materials

“Smaller, faster, and cheaper” has been a goal of electronics manufacturers for decades, and for the most part they have achieved it. But if the momentum is to continue, companies will need an arsenal of new materials to further shrink the size and price of components while adding properties such as flexibility.

Exotic materials such as graphene, carbon nanotubes, bendable glass, and high-performance polymer films—applied with traditional printing techniques—could be the answer, materials providers said last month at the Printed Electronics USA conference in Santa Clara, Calif.

These new materials can help print circuitry, semiconductors, and other electronic components on paper, plastic, or glass with methods similar to those used to make books and magazines. Cheaper than the deposition and etch methods needed for conventional electronics, the process can yield inexpensive devices for lighting, data storage, and radio-frequency identification tags. But mindful of markets beyond those of the conference’s title, attendees also promoted integrating their materials into conventional electronics as well.

Notable was the participation of large materials companies—including DuPont, Solvay, and Merck KGaA—at the exhibition accompanying the conference. A few years ago, smaller firms and equipment makers were the main exhibitors. In all, 1,500 people attended the event.

Still, the exotic materials are not a big segment of an overall electronic materials market, which the consulting firm Prismark Partners values at about $150 billion a year. With graphene, for example, governments, venture capitalists, and others have invested more than $40 million in start-ups, an analyst said. But to date those firms have sold less than $10 million of materials, mostly for research.

However, Harry Zervos, a senior technology analyst with IDTechEx, the firm that organized the conference, said, “A lot of what the conference is about is taking an abstract idea and translating it into a concrete solution.” Many ideas may prove to be impractical, he said, but others may turn into tomorrow’s billion-dollar materials.

Some attendees came to the event with a wish list of things they want electronics to do. “The world of tomorrow will feel, respond, and compute,” said Ivan Poupyrev, a senior research scientist at Walt Disney Co. He was at the conference to find ways “to get there.” One way Poupyrev described was “Botanicus Interacticus,” a technology he developed to include a plant in an electrical circuit so that it makes different sounds depending on where it is touched.

In a more down-to-earth discussion, Slade Culp, staff scientist at building and aerospace systems manufacturer United Technologies, said his firm is interested in such things as printed electronic sensors in aircraft to diagnose failing parts and printed heaters embedded in wings to ward off ice formation.

Among materials suppliers, the use of graphene was a hot topic, thanks to the award of the 2010 Nobel Prize in Physics to Andre Geim and Konstantin Novoselov. The two scientists are credited with discovering the material, a one-atom-thick sheet of honeycombed carbon that boasts exceptional mechanical and electronic properties.

The scientists’ work suggests that graphene could enable a new generation of low-power, high-performance electronics for computer and communications applications, Chagaan Baatar, a program officer with the U.S. government’s Office of Naval Research, said in a keynote speech. The Navy is now supporting research at academic institutions on graphene for electronics.

“Graphene is still in its early days, but its development is moving fast,” said IDTechEx analyst Khasha Ghaffarzadeh. The material comes in many types that have different quality and performance characteristics.

The material might nudge its way into the $1.6 billion market for the transparent conductive layer that makes computer and phone screens touch sensitive. The indium tin oxide that dominates that market can crack when it bends, but graphene does not. That means the one-layer carbon sheets could be used in a new generation of bendable displays, Ghaffarzadeh said.

Or graphene’s high surface area relative to its volume could enable a new generation of supercapacitors that store large amounts of power. Ghaffarzadeh said these capacitors could be simple, cheap competitors to lithium-ion batteries for mobile phones and cars in what he projects will be an $11 billion market by 2023.

Graphene has started to play a role in conductive inks, which are needed to connect components in printed electronics. The most common inks are made of silver, an effective but expensive conducting material.

Vorbeck Materials, a six-year-old start-up based on technology licensed from Princeton University, has already commercialized a line of graphene inks.

According to Vorbeck President John S. Lettow, the packaging firm MeadWestvaco is using his firm’s inks to print circuitry between the cardboard layers of packaging. The circuits are part of electronics that replace the bulky clip-on security tags often found on high-end goods. Vorbeck runs an ink facility in Jessup, Md., with 40 tons per year of capacity and plans to open a 100-ton facility in Pocomoke City, Md., later this year.

Near term, the firm is working “to make sure our inks work on standard high-speed industrial presses,” Lettow said. The company is also exploring opportunities for graphene in batteries and supercapacitors, he said.

About $1.5 billion worth of materials is sold annually for use in printed electronics, said Jonathan Melnick, an analyst with consulting firm Lux Research who attended the IDTechEx conference. Silver-based inks for printed electronics now account for $1.4 billion of those sales. They mostly end up as conductors in solar modules, electronic membrane switches, and radio-frequency identification tags used to track shipments.

Melnick is optimistic about the future of inks in these established uses and figures they will be worth $2.4 billion in 2017, with identification tags and medical applications growing fastest. Also promising are techniques using silver nanowire printed films to replace indium tin oxide for touch screens, he said.

In fact, silver nanowire technology developed by companies such as Cambrios, founded by scientists from Massachusetts Institute of Technology and the University of California, Santa Barbara, is already commercially viable, Melnick pointed out. According to Cambrios, the Huawei Ascend smartphone uses its ClearOhm film.

As for graphene, Melnick doesn’t expect to see it used in touch screens. It is, he said, “overhyped, more expensive, and not realistic for commercial adoption” compared with the silver alternative. For the same reasons, he doesn’t expect that carbon nanotubes will work in this application any time soon.

But carbon nanotubes, the rage among materials scientists in the 1990s, are further ahead in their development than graph­ene, said David J. Arthur, chief executive officer of SouthWest NanoTechnologies, a University of Oklahoma spin-off. With the help of the electronic materials firm Brewer Science and $6.5 million from the National Institute of Standards & Technology, SouthWest developed technology to improve control of the optical and electronic properties of its nanotubes, Arthur said.

In the near term, Arthur expects the advance in control will enable a new generation of three-dimensional printed membrane switches. In time, he hopes improvements in carbon nanotube conductivity and transparency will give his firm a shot at touch-screen film applications. He speculated that combinations of carbon nanotubes and graphene might further improve the electrical performance properties of a replacement film.

Materials suppliers also described new flexible substrates for printed electronics. Waguih S. Ishak, a vice president of glassmaker Corning, said the firm’s latest advance, Willow Glass, could bend and wrap around printing press rollers, making it ideal for printed electronics.

Iryna Yakimets, a program manager at Holst Centre, a Netherlands-based flexible electronics research organization, described efforts to replace rigid glass in mobile phone displays. Holst and the high-performance polymer maker Victrex developed an improved polyarylether­ketone film touted as being able to replace glass in a new generation of flexible ­displays.

A lot of work still must go into optimizing the technologies discussed at the conference, IDTechEx’ Zervos acknowledged. In time he expects the best of them to make it to market. But, he cautioned, “don’t expect them to be ubiquitous ­overnight.”