What if your clothes could charge your cell phone? Imagine wearing fabric made from photovoltaic textiles acting as solar panels that could charge a mobile phone. Researchers at the University of Exeter in the UK have developed a new photoelectric device that is both flexible and transparent. At...
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What if your clothes could charge your cell phone? Imagine wearing fabric made from photovoltaic textiles acting as solar panels that could charge a mobile phone. Researchers at the University of Exeter in the UK have developed a new photoelectric device that is both flexible and transparent.
At just a few atoms thick, the newly developed technology converts light into electrical signals by exploiting the unique properties of the recently discovered materials graphene and graphExeter. (GraphExeter is the best known room temperature transparent conductor, and graphene is the thinnest conductive material.) Its efficiency is comparable to that found in opaque devices based on graphene and metals, noted Saverio Russo, professor of physics at Exeter. Metallic nanostructures in “smart” materials typically cause a haze that prevents them from being truly transparent, but the photosensitive device developed at Exeter contains no metals and is completely transparent. It can detect light from across the entire visible light spectrum, so it is as efficient at sensing light as other recently developed opaque photoelectric devices.
“We are only just starting to explore the interfaces between different materials at very small scales and, as this research shows, we are revealing unique properties that we never knew existed,” Russo shared. In the not-too-distant future, photosensitive materials and devices such as this could be used for intelligent windows that are able to harvest electricity and display images while remaining transparent, he and his colleagues suggested. Other “smart fabric” applications include the production of athletic wear that could track a runner’s heart rate or medical bandages that could monitor a patient’s vital signs. Military and security agencies are exploring such technologies for their ability to serve as sensors that could alert their wearers to chemical or other hazardous exposures.
Separately, at Georgia Tech, a team led by Mano Tentzerisis has used inkjet-printing technology to combine sensors, antennas, and a silver nanoparticle ink emulsion into a device that gathers energy out of thin air. It pulls low levels of energy from the electromagnetic waves emitted by radios and radar. This line of research could someday lead to self-powering electronic devices.
More traditional “futuristic” technologies include printed electronics, which is a set of printing methods used to create electrical devices on various substrates. The term printed electronics is related to organic electronics or plastic electronics, in which one or more inks are composed of carbon-based compounds, according to Wikipedia. These other terms refer to the ink material, which can be deposited by solution-based, vacuum-based, or some other method. Printed electronics, in contrast, specifies the process, and can use any solution-based material, including organic semiconductors, inorganic semiconductors, metallic conductors, nanoparticles and nanotubes.
Advances in printed electronics are making traditional paper come alive. Circuits now can be printed on posters and other traditional displays, making them interactive to the touch—for example, by playing clips of songs when someone presses on a printed advertisement for an upcoming concert. OLED (organic electroluminescence display) technology is popping up in the form of illuminated displays, such as flexible, tough, eye-catching ads. OLED uses printed layers of carbon-based particles that convert electricity directly into light.
Earlier this year, LG Electronics put the world’s first curved OLED television on the South Korean market. Printed with organic light-emitting diodes, the television is 0.17 inches thin. The new model retails for more than $13,000 USD but competition may soon bring sticker prices down. DuPont previously announced the ability to print its own 50-inch set in two minutes.
Got a Web Press?
What does all this techno-babble have to do with the conventional printing plant? Scientists at the renowned Palo Alto Research Center (PARC) in California contend that anyone with a large roll-to-roll, web-offset printing press can have a future in electronics manufacturing, printing electronic components such as sensors, transistors, light-emitters, smart tags, flexible batteries, memory, and smart labels. Already, PARC’s printed logic circuits drive printed memory manufactured by Thinfilm Electronics, which manufactures printed temperature sensors for perishable food packages.
Although PARC is a division of Xerox, “it is not developing the new technology for its parent,” as CNET/CBS Interactive reported in May. “Rather, it is working in conjunction with private companies and academic institutions to try to break new ground in the field of printable, functional electronics.” Janos Veres is PARC’s program manager for printed electronics, and at the core of his work is a blending of material science and printing technologies. That means developing a series of special inks that incorporate the desired functionality, be it sensing, light-emitting, or even chips. “You make inks and print with those inks,” Veres told CNET. “And you only put it where you need it.”
As mentioned above, one method for printing electronics employs traditional inkjet print heads. But rotogravure and flexographic methods also are employed. In fact, gravure printing of electronics is of significant interest due to its ability to print high-resolution features and thin layers having uniform morphology. In January, PARC and Clemson University’s Sonoco Institute of Packaging Design and Graphics received an award from the FlexTech Alliance (see sidebar) to transfer and optimize functional printing technology from lab scale to a commercial printing press. The collaborative project spans laboratory and high-volume commercial scale printing processes 20 inches wide and up to 660 feet per minute. (The FlexTech Alliance R&D program is supported by the U.S. Army Research Laboratory.)
Market research consultancy IDTechEx has projected that the paper electronics market—estimated at some $16 billion this year—will grow to nearly $77 billion by 2023. “Print service providers [PSPs] can look to integrate simple printed electronics components into functional finished devices,” encouraged IDTechEx CEO Raghu Das. “This is an area of undersupply in the industry—there is a lot of material and component innovation, but few [are] creating complete products.” One company heeding Das’s advice is Novalia, a Cambridge, UK, printing firm where electrical circuits made by printed ink are helping to create a new generation of “intelligent” greeting cards, books, and other interactive paper-based products. (See “Specialized Print Apps”)
Near-field communication (NFC) is a related concept – an evolved form of the RFID solutions used for open-road tolling on highways. Since gaining mainstream traction two years ago, NFC technology now is bundled into more and more smartphones, including the Android-powered Samsung Galaxy S4. As a result, consumers are beginning to use NFC for more than mobile payments. What if you could tap your phone to unlock a door, sans keys? That reality may not be far away, thanks to NFC. In a real-world example, an Asian library has enabled a new use of the wireless technology, which is akin to a low-power Bluetooth that can transfer very small amounts of information, such as a URL or a payment. The key to NFC is that the item sending the information does not need any power: Badges and stickers can deliver information to a phone with a tap.
Hanno Library has installed approximately 100 tags, called “Tatchitagu” and provided by Fujitsu, on its shelves in Japan, where mobile phones with NFC are more common. There, the technology is employed to replace credit cards and subway passes. Library visitors can tap their phones on the tags to receive all kinds of information, including Wikipedia links to authors, pictures, and reviews. The tags also access services: If someone wants to review books or recommend them to other readers, he or she just taps and types. The system even facilitates check-out.
Here’s how it works, as described by Popular Science: NFC is a short-range, low-power communications protocol between two devices. One device, the initiator, uses magnetic induction to create a radio-wave field that the target can detect and access, allowing small amounts of data to be transferred wirelessly over a relatively short distance. (In NFC’s case, the distance must be less than four inches.) The difference between NFC and RFID is that the latter is a one-way street: The EZ-Pass transmitter beams the $4.25 toll to the tollbooth’s receiver, for instance, and that’s the extent of the transaction. But NFC is two-way, allowing NFC-enabled gadgets to send and receive information.
Compared to other wireless protocols like Wi-Fi or Bluetooth, NFC is exceedingly slow, with a maximum data transfer speed of 0.424 Mbps (or less than a quarter that of Bluetooth). But NFC has several key advantages: It consumes a mere 15 mA of power, which is practically nothing for today’s jumbo smartphone batteries; it has the possibility for greater security; and it forgoes the involved “pairing” process of Bluetooth entirely. Bluetooth needs to be configured; NFC is completely effort-free, requiring nothing more than a tap.
Big Indian Believer
Rigid, bulky lithium batteries have long set limits on the design of small electronics. But printed electronics technology allows the production of customizable, thin-film green batteries. These flexible alternatives may have a bright future in wearable electronic clothing and medical implants—or they might make possible a mobile phone as thin as a credit card. Several companies are now designing such batteries using printing methods much like those employed to make silk-screen T-shirts—but they lay down layers of electrochemical inks made of zinc, metal oxide, and electrolytes, rather than fluorescent dyes.
Mega printer RR Donnelley sees the potential and has become a believer in NFC and RFID products. In 2011 it claimed an equity position in Solicore, a leader in embedded power solutions, wherein the partners commercially agreed to develop printed batteries. This past April, the $10-billion Donnelley introduced innovative RFID and NFC production capabilities as part of its printed electronics strategy. These new capabilities enable the company to provide customers with unique printed NFC and RFID tags that can be embedded in a range of other Donnelley-produced products, including retail displays, product packaging, shipping labels, direct mail pieces, catalogs, and magazines.
“Our Digital Solutions offering is ideally positioned to help our customers create and execute extended consumer experiences,” explained Ken O’Brien, RR Donnelley’s chief information officer. “For example, we can produce interactive retail displays that direct customers to mobile optimized sites featuring content marketing and video, all of which we can help to create.”
CEO Thomas Quinlan added, “Now we offer customers single-source convenience and control as we produce their RFID and NFC tags and integrate them with other materials that we create. Even more, we can develop and host the mobile consumer experience initiated by interactive NFC tags and even provide response analytics about the programs’ effectiveness.” Ronnie Sarkar, Donnelley senior VP of technology innovations, stated: “The printed electronics solutions that we continue to develop significantly boost production flexibility. We can very quickly change the production line to accommodate different specifications, dramatically reducing the cycle time associated with bringing RFID and NFC tags to market.”
Donnelley’s manufacturing process allows customers to take advantage of flexible antenna design and production capabilities that tune the performance of their tags to specific applications for enhanced performance. The firm’s offering includes a complete suite of antenna design, testing, and proof-of-concept services to help customers identify optimal designs.
In related news this past spring, German RFID manufacturer Mühlbauer and NovaCentrix, the Austin, TX-based leader in printed electronics manufacturing technologies, established a formal collaboration for developing a flexible and cost-effective new RFID antenna printing technology. Under the agreement, Mühlbauer is developing, producing, and marketing scalable antenna production systems (APS) for RFID inlay/label manufacturers. These APS incorporate NovaCentrix’s patented PulseForge photonic curing tools. Unlike traditional oven technologies, the transient PulseForge process cures functional inks and thin films in milliseconds on low-temperature, flexible substrates such as paper and plastic -- without heating or damaging the underlying or adjacent substrates. Meanwhile, the low-cost Metalon ICI series of inks are formulated with copper-oxide nanoparticles along with a reduction agent, in water. After the ink is printed, PulseForge drives a reduction reaction, thereby converting the copper oxide into a thin film of highly conductive copper. This process is performed in ambient air on low-temperature substrates at speeds exceeding 98 feet per minute.
With this step Mühlbauer completes its long-term strategy to provide a complete turnkey solution for realizing the most flexible, fully integrated, and cost-efficient RFID factory, including antenna production, inlay assembly, label converting, and personalization, the firm said. “We believe partnering with the NovaCentrix team is in the long-term best interests of Mühlbauer and our customers for realizing the most efficient RFID antenna manufacturing – directly before attaching the chip,” noted Thomas Betz, management board member for Mühlbauer.
NovaCentrix CEO Charles Munson reported: “The first version of the reel-to-reel antenna manufacturing line, ‘APS 20000,’ will be designed to provide a capacity of 100 million antennas per year. The system consists of modules for printing, drying, photonic curing, and quality control …. The goal of this highly flexible and scalable concept is to further increase the competitive advantages of the RFID inlay and label manufacturers by enabling them to produce their antennas in house with very short reaction times and to achieve further cost reduction by a significantly improved cost of ownership, especially for antennas on paper substrates.”
Offering an option to RFID is Colorbit USA. The U.S. division of Japanese company B-Core, Colorbit was launched this year to introduce a new color-coded automatic identification to the North American and European markets. The technology enables users to track goods or assets via a printed or painted color code captured by a digital camera. Users can track inventory or assets via unique colored patterns as an alternative to serialized bar codes or radio-frequency identification.
The system consists of B-Core’s software that provides a series of unique colored cells representing a serial number. A user would print each pattern on a label that is then attached to an item, or paint that pattern directly onto that object. The code could also be generated using tri-color light-emitting diodes (LEDs) installed on the asset. When a digital camera in a mobile phone or tablet PC, or a fixed camera, captures the image of a Colorbit scheme, the software determines its serial number, thereby identifying the goods.
The technology offers a lower-cost alternative to RFID, according to Chris Anderson, Colorbit USA’s managing partner, because it does not require readers, or even tags, since users can print a Colorbit label themselves on any color printer. It does require a clear line of sight, however, so the labels or painted Colorbit codes must be facing the camera. The pattern of colors could be printed in a variety of form factors, including a spiral, making them more attractive to product designers. In addition, they need not be scanned individually—a single photograph containing multiple printed labels will capture all of them.
Futuristic Learning at the PRINT 13 Show
The Future Print Pavilion at the quadrennial PRINT 13 show in Chicago (September 8-12, www.print2013.com) will showcase resources and expertise to guide graphic communications professionals into the future, said show manager the Graphic Arts Show Co. (GASC). Among the hottest new and emerging print technologies featured are RFID, printed electronics, and 3D printing. (See also www.myprintresource.com/article/10941568.)
Featured on the show floor inside the pavilion, which is sponsored by FlexTech Alliance, will be the “Experiential Lab” where attendees can get up close and personal to examine and learn more about key emerging technologies. In addition, there will be a specialized Future Print seminar track. Among the educational offerings are:
- “The Future of Print” by industry guru Frank Romano
- “Printed Electronics/Functional Imaging: Advanced Workflow and Printing Techniques” by Cal Poly's Colleen Twomey
- “Printed Electronics: How to Implement Your Next Profit Opportunity” by Cal Poly's Xiaoying Rong
- “3D Printing for the Commercial Printer” by Julie Shaffer of Printing Industries of America
- “21st Century Print Technologies Explored” by media consultant Steven Schnoll.
“Printing technologies and opportunities are always changing and expanding,” said GASC president Ralph Nappi. “Today’s graphic communications professionals use technologies that were unheard of 10 or 20 years ago. Attendees at PRINT 13 will be able to explore new and emerging technologies that one day will be seen as routine profit centers.”