In the near future, wiring harnesses, connectors and other electrical components may be printed with the touch of a button. Printed electrical systems are an offshoot of printed electronics, a fast-growing field.
Printed electronics are based on flexible substrates of functionalized polymer films that are less than 1 millimeter thick. “The market potential for printed electronics is huge,” claims Wolfgang Mildner, chairman of the Organic and Printed Electronics Association (OE-A). “Thinness, flexibility, robustness and easy integration are the competitive advantages of this new technology.”
Klaus Hecker, OE-A’s managing director, believes there could be numerous applications for the technology in the auto industry. “By mid decade, there will be fully integrated, smooth and aesthetically pleasing interiors with embedded displays and switches,” he predicts. “They will show only when needed and be activated by slight touch.
“This will also pertain to the exterior: very thin, yet brilliant organic LED backlights [will be] directly glued to the car body,” Hecker points out. “Printed conductors [will] connect with the car’s electrics. [There will be] no screws, no parts protruding to the densely packed innards.”
“Completely printed and laminated replacements for instrument clusters and wiring will save weight, cost and space in cars,” adds Peter Harrop, chairman of IDTechEx, a consulting firm specializing in printed electronics. “Wireless sensors and actuators will also save wiring in future vehicles and gradually be printed themselves.”
Conductive inks will allow manufacturers to print some electrical systems. “The technology has the potential to be applied to composite panels used in aircraft fuselages and automotive bodies,” says Stan Farnsworth, vice president of marketing at NovaCentrix, which has developed a copper ink called Metalon.
“True copper inks are available for screen, flexographic or gravure application,” adds Farnsworth. “In conjunction with our PulseForge technology, these inks can be applied to substrates such as plastic films and even paper.”
The PulseForge tools use brief, extremely high-powered pulses of light from custom lamps to sinter inorganic inks and films at room temperature. The combination of Metalon and PulseForge allows conductivity requirements to be met using thin, flexible substrates. Most substrates remain unaffected because of the very short pulse duration.
“There’s been a lot of interest in this process,” says Farnsworth, a mechanical engineer. “Most of the focus has been in the packaging industry, but it also has a lot of potential to replace traditional wiring in many industries. We’re currently working with some aerospace and military manufacturers.
“Printing is an additive process,” Farnsworth points out. “You put it where you want it. You’re not adding a wire after the fact. It allows you to get away from traditional wiring harness restrictions, such as size and weight. Printable electrical systems can also eliminate several design and assembly steps, which reduces cost and complexity. And, we use water-based inks to achieve a green manufacturing process.”
However, Farnsworth says copper ink technology still needs more development. For instance, “we’re currently at about half the conductivity of wire,” he explains. “We’re addressing issues relating to moisture, temperature and humidity.” A
Learn more about the future of wire by clicking www.assemblymag.com and searching for these articles: