The printed electronics market is growing at a rapid pace as the number of applications explodes. Lighting and sensors in our increasingly autonomous cars, thin unobtrusive patches moulded to our skin which enable doctors to check up on our health or curved and ultra-thin smartphones - all these could not be produced were it not for printed electronics.
Using various printing methods, thin, lightweight, flexible, robust and environmentally-friendly electronic products can be created and mass-produced. Electrical components can also be integrated directly into low-cost reel-to-reel processes. The implications are huge for a wide array of industries from packaging to automotive. According to figures released by the German-based Organic and Printed Electronics Association (OE-A), the market as it stands today is worth USD 30 billion and could very well double in coming years if the results of high-end research find a way into mass production.
Currently, organic light emitting diode (OLED) displays are the fastest growing segment of the printed electronics market. Mass-produced, these flexible and thin displays are used in all sorts of ways, integrated in the most recent car models, in the most up-to-date smartphones or in the latest TV sets.
“OLED taillights are today in series production at several German car manufacturers. Due to their extremely thin and flat shape, they enable new form factors and design options. In addition, prototypes of flexible and three-dimensional OLED taillights have been shown recently. In the future, as autonomous driving becomes the norm, we expect curved and ergonomic OLED screens to become widespread in cars as people require more information as well as entertainment,” says Klaus Hecker, Managing Director of the OE-A. “Printed sensors for recognition of seat occupancy are already used in almost every car, in relation to airbags, for instance, and we expect other sensor-based applications for the car to be a big growth area for our industry as well,” he adds. One of the promising areas of research is in smart and energy-harvesting tyres, for instance.
Curved OLED TV sets are no longer a rarity: at least five consumer electronics manufacturers have launched these sets on the market in 2017 and prices are coming down rapidly. Their thin and curved appeal, as well as their lower energy consumption will undoubtedly make them increasingly popular in years to come.
Likewise, an increasing number of smartphone manufacturers are beginning to produce devices with OLED screens. One Korean manufacturer, in particular, has been ahead of the game in that area but others are beginning to follow that company’s lead as the appeal of a curved and very thin phone delights design aficionados.
Sensors are frequently used in cars now, but this application for printed electronics is also exploited in many other industries, from medical to packaging. Increasingly small and body-conformable medical patches equipped with sensors enable doctors to monitor their patients’ health, for instance.
Sensor labels can be stuck on a wide variety of produce and can pick up information such as temperature changes, humidity levels or even chemical variations. This information can be used in the packaging industry to locate and monitor goods. ”The potential for the packaging industry is huge but there is a cost factor that needs to be overcome as packaging is produced very cheaply,” admits Klaus Hecker.
Solar cells have become a feature of our cities in this increasingly environmentally-conscious age. We are used to seeing these rigid panels on the roofs of our homes or on other buildings across town.
Solar cells could be even more widely used if they were created using printed electronics. Curved and thinner panels could be envisaged, fitting on other surfaces, for instance the roof of a car. The ability to mass-produce them in the same way as banknotes would render them much more affordable and ubiquitous.
Small, thin and flexible photovoltaic (PV) devices on films are already being made that are lightweight and translucent. They use little material and generate electricity even in low light.
The challenge is to print the thin pinhole-free layers required for photovoltaic cells over more than 1 m2. The precision and laser processing required are not there yet although researchers are working hard to find the appropriate solutions.
The IEC is encouraging standardization in the field of printed electronics as it is essential in enabling the technology to be widely used across a variety of industries. The IEC technical committee (TC) leading the way in this area is IEC TC 119: Printed electronics. The IEC 62899 series of International Standards has been adopted under its remit.
The technology for printed electronics is evolving fast. Material scientists and engineers have dedicated their efforts to improving nanostructures of conductive material, ink formulations and printing procedures. According to Klaus Hecker “stretchable electronics is a very interesting technology as it enables the seamless integration in new applications like smart textiles. Another new field is the combination of printed electronics and 3D printing/additive manufacturing.”