Emerging printed electronics are as diverse in application and design as they are flexible. These technologies integrate specialized inks on a wide variety of flexible substrates to produce a vast array of items including lights, heaters, flex circuits for wearables and smart garments, electronic components, and the list goes on.
The exhibition floor at IDTechEx 2016 hosted some nifty prototypes and demonstrations from experts in printed electronics. Here are some of the intriguing technologies we found:
SP Technology has transformed standard flexographic printing processes to allow them to print electronics onto substrates such as paper, plastic, and textiles. Using a custom ink on a PET substrate, they are able to print very thin LED light spread. The printed lighting produces an extremely bright effect due to the design.
Figure 6. Printed LED lights on a paper-thin PET substrate from SP Technology
SP Technology has also partnered with NthDegree to produce the Nth-Light. The printed LED Nth-Light is paper-thin, light, extremely flexible, and has a low operating temperature. To make the Nth-Light, LED wafers are cut down using a specialized process into micro LEDs the same size as ink particles and then suspended in the ink for printing. Given the unique form factor and low operating cost, the printed light could be used in a number of applications. Some current end products of this technology include advertising backlighting, lighting for beverage coolers, and retail shelf lighting.
Figure 7. The Nth-Light is a highly flexible and very thin printed LED spread.
SP Technology also demonstrated a printed heating array. One of the unique features of the heater is that the ink is self-regulating, meaning that it cannot heat above a certain temperature. This allows for the technology to be integrated in places where there is safety concerns about the use of traditional heating or is there is concern for hot spots.
Figure 8. Using a 9-volt battery, this printed heating array can heat up and cool down very quickly and uses specialized temperature-regulating ink.
TF Massif won the ‘Best Product Development Award’ in Printed Electronics for its large area printed electronic circuit. The substrate is a 50 micron thin PET material produce on a 1 meter wide web. The resulting material can be utilized to create large lit advertising backplanes that remain super-thin, and are achieved at very low cost. TF Massif’s effective printing process fills the need for efficiently producing large area and high volume printed circuits.
One of the impressive features of printed electronics is the ability to re-invent devices that are normally bulking to be paper-thin. Material supplier PiezoTech, for example, has made printed speakers with their electroactive printed polymers. Their specialized polymers are designed to convert electrical energy into mechanical energy and vice versa. The speakers work due to the vibrational movement of the polymers when electric voltage is applied. With this technology, virtually any surface could be transformed into a speaker, including the backs of phones, perhaps advertisements, and the list goes on.
Figure 9. The large circle in the lower right-hand corner is an actual working printed speaker.
Textiles and wearables are also very prominent applications for printed technologies. Insulectro demoed one such example of combining printed technology in smart garments/wearables. The Komodo AIO Smart Sleeve is designed to measure EKG, heart rate, blood oxygen, body temp, and other parameters. The sleeves sensory capabilities are established by silver conductive ink printed on TPU connecting electrodes at the top and bottom of the sleeve.
Figure 10. Outer view of the Komodo AIO, the world’s first activity monitoring compression sleeve
Figure 11. Komodo AIO Smart Sleeve provides 24/7 ECG/EKG monitoring and stores data on the AIO App for analysis.
Figure 12. Example of silver conductive inks like the one utilized inside the Komodo AIO Smart Sleeve to connect the upper and lower electrodes.
Creative materials also uses silver conductive ink to make flex circuits for wearable applications. When printed onto a urethane-based substrate, the resulting flex circuit can be used for a wrist-worn wearable. The substrate and ink even stand up to multiple washing cycles, making it feasible to integrate to make other forms of smart garments or textiles.
Figure 13. This printed circuit from Creative Materials holds up to multiple washing cycles.
While there has been much focus on flexible, plastic-based substrates in printed electronics, Arjowiggins Creative Papers had bridged electronics with the most ubiquitous and renewable substrate utilized in our everyday lives, paper. Their award-winning PowerCoat line of intelligent paper allows for direct printing electrical components (such as sensors, LED lighting, battery electrodes, antennas, chips, passive components, etc.) on ultra-smooth and highly temperature resistant paper, resulting in smart products that can track and convey a multitude of information and supply interactive experiences. Promising application avenues include packaging (tracking, content status, lighted or interactive), event tickets (informative including entry access, GPS coordinates, etc.), invitations and labelling (informative), interactive gaming, and customer relations. Security applications and medical wearables are also possible uses of this technology.
The power to transform ordinary surfaces into smart surfaces is also making a significant impact in printed electronics. ISORG is pioneering large area organic photodetectors and image sensors. In contrast to silicon-based sensors, ISORG’s innovative materials are extremely thin, light, and cost competitive. Their organic photodiodes on plastic can be used to create smart surfaces for object detection, touchless user interfaces and gesture recognition, and sensors for IoT applications. The large area image sensors, printed to either glass or plastic substrates, having promising applications in x-ray digital imaging, diagnostics, and consumer electronics.
As advancements continue in 3D printing and printed electronics, there will likely be a sustained trend towards more function, reliability, and customization, with less cost and production time for innovations. It seems as if we are just now breaking the barrier of what is possible with these technologies. Both divisions are still working out some of the major issues, but as with most other technological breakthroughs, it seems that the emerging developments will drive these processes to become the new ubiquitous standards of manufacturing in some arenas.