INNOVATION


Printed electronics: technology that connects and impacts

10/02/2021

CATEGORY: packaging systems BRAND: ITENE

In an increasingly connected world, data and the ability to extract information about how, when or how consumers use the products they purchase is a great tool to better respond to market needs. In this sense, incorporating electronics into packaging opens the door to a world of new possibilities for the packaging industry.


Inmaculada Lorente – ITENE

 

One way of making this a reality is through the use of printed electronics. By means of this technology, electronics devices will be directly printed on the packaging materials and will allow for example the sensorization of product conditions, or even print graphics in movement on the packaging material.

 

 

Printing electronics brings together two sectors as different as electronic design and printing processes. Basically, this technology consists of printing "electronic" inks to develop antennas, matrixes or circuits on different substrates, as varied as paper, textile or plastic. By printing directly on these substrates, it is possible to create, in a relatively economic way, objects that react electronically.

 

The end markets with the greatest potential for the use of printed electronics include such as automotive and transport, consumer electronics, healthcare, retail and packaging, aerospace and defence, construction and architecture. For most of these markets, the attractiveness of printed electronics comes mainly from the possibility of preparing microstructured layers in a much simpler and more cost-effective way compared to conventional electronics. The devices developed are thin and flexible, which facilitate the use of low-cost electronics in applications such as solar cells or photovoltaic panels for solar energy production, radio frequency identification (RFID) tags and antennas for product tracking, surveillance devices, memory devices for data storage, display screens, wereables, lighting, batteries and sensors.

According to estimates made by Markets and Markets, the printed electronics market is expected to grow from $7.8 billion in 2020 to $20.7 billion in 2025. Among the main factors driving the market growth are the increased use of printed electronics for the development of smart and connected devices, the growing global demand for flexible, thin and low-power consumer electronics, the high demand for next-generation flexible printed electronics and the significant cost advantages offered by printed electronics. In the packaging sector, according to IDTechEx estimates, the market for smart packaging will be $206 million by 2025. E-commerce and the globalisation of international trade are expected to stimulate the demand for solutions such as RFID tags and smart labels, which enable manufacturers to protect themselves against counterfeiting and to improve the control of their products during distribution.

 

Printed electronics: an opportunity for packaging industry

In order to achieve these numbers, the printed electronics industry is constantly evolving. New materials, processes, equipment and designs are constantly being developed to transform ideas into real products. In this ever-changing environment, industries that have not traditionally been associated with electronics, such as packaging or labels, are seeing the ample opportunity for innovation and growth that this technology offers. Like conventional printing, printed electronics apply layers of ink on top of each other, making the consistent development of printing methods and ink materials one of the industry's key tasks.

The inks used for this purpose are different, depending on the function they have in the whole printing process. Thus, in the printing of an NFC antenna it would be necessary to print a conductive ink, through which the current would circulate, and a dielectric ink that would act as an insulator. Conductive inks are mostly formulated using silver as conductive material, which makes them expensive for short print runs. There are also inks based on other metals, such as copper, which are more economical, but have limitations such as oxidation under normal environmental conditions and therefore loss of conductivity. In order to increase the supply, lower the price and reach applications where this is not currently possible to use this technology, various companies and research centres are working on achieving economical and environmentally resistant conductive inks based on other compounds.

An aspect that is also relevant, but just as important, is the type or nature of the ink to be printed is the printing system to be used. Each printing system has inherent characteristics that make it more or less suitable for printing one type of device or another. The printing system traditionally used has been screen printing, mainly due to its high printed layer thickness and facility of preparation. However, in recent years, inkjet printing and, therefore, the formulation of inks for this printing system is growing. One of the main reasons for this is because thinner and more flexible devices are increasingly required and therefore thinner lines are required to be printed. On the other hand, the ease of prototyping offered by this printing system is also causing its use to grow, as is happening in the printing industry in general. Most of the inks available on the market are formulated for these two printing systems. In addition, they are usually solvent based and thermally cured. However, some flexographic printing inks can be found on the market.

Also, UV-curable conductive inks are available on the market. Although this curing technology is widely used in the label printing industry, the use of these inks in electronic printing is still sporadic. As they increase their application in labeling for the development of connected packaging, the availability of such inks will become very important.

Regarding to the printing system, although screen printing and inkjet are the most widespread, each printing system has its advantages and limitations. The table shows a summary of the main characteristics of the most commonly used printing systems in packaging printing and their advantages and disadvantages for use in electronics printing.

 

 

 

As explained, electronic printing consists of printing inks to develop electronic devices. One of the objectives is to use traditional printing techniques on packaging to enable their rapid adoption by this industry. However, not all the components that are necessary for electronics to work can be printed. The printing of electronics on flexible substrates combined with the use of conventional electronic components is called hybrid flexible electronics. In this sense, the way these components are joined to the printed lines or tracks is done by the use of conductive adhesives and the way they are applied depends on the size of the component to be hybridised, the speed required, the nature of the adhesive to be used, etc. For example, in the development of an NFC printed communication sensor, the antenna would be printed but the chip would be connected to this printed antenna via a conductive adhesive.

European Commission, through various funding programmes, has allowed companies and research centres to generate knowledge in this area and to equip themselves for its development. With the aim of transferring these results to industry and developing products that are marketable and boost Europe's economy, the European Union has financed projects called "test beds". These projects consist of bringing together centres that are pioneers in certain technologies, which will make their facilities available to any company that wishes to apply this technology to its products. One of these projects has been LEE BED (Grant agreement No. 814458) in which ITENE, together with 16 other partners, aims to respond to the challenges of electronic printing, facilitating its facilities and thus allowing faster development and pilot-scale manufacturing of nanomaterials, electronic inks, adhesives and multifunctional composite materials. From January 2021, the LEE-BED project, and with it ITENE, will open its doors to industry, so that all companies interested in accessing its infrastructure and transforming their ideas into prototypes for further validation can submit their interest. The proposals received through the project website (https://lee-bed.eu/) will be evaluated and 5 of them will be developed from August 2021. This initiative will give a boost to current printing processes, considering that they have already reached a level of maturity that offers an alternative for the manufacture of large-area electronic components.

 

 

The end user companies, that are part of the project, are Maier, Acciona, Grafietic and Swarovski, and different prototypes incorporating printed electronics are being developed for these companies. These developments range from the incorporation of printed electronic components for lighting and contact in the interior of cars, sensorisation of structures, the development of intelligent labels or the combination of printed electronics with jewellery for various applications.

The printing and packaging industry is changing as packaging becomes more than just an object and printing becomes increasingly functional. There have been successful retail projects driven by marketing campaigns, for example, with flexible lighting included in the packaging or for customer interaction through NFC labels. In 2019, CocaCola launched a batch of bottles whose logo, printed on a plastic label, illuminated when pressed by the consumer. As regards the use of NFC, the most public examples are the use of NFC in products such as spirits, wines or liqueurs, for consumer engagement. Examples of such applications are Pernod Ricard's Malibu campaign or the example of Barbadillo wineries in Spain.

 

 

 

However, NFC technology can also have other applications. Selinko, an identification platform for authentication, illegal market detection and consumer engagement, and Toppan Printing, a Japanese global printing company, collaborated to launch an innovative device that can detect any attempt to remove, tamper with or even puncture the cork of a wine bottle. The device combines a new generation Toppan sensor attached to an RFID/NFC tag and powered by Selinko's platform and a mobile application for authentication. The sensor is located at the top of the bottle, below the capsule, and can detect any attempt to remove, manipulate or pierce the cork, as well as access extensive information about the winery, the grape and many other issues relevant to the specific bottle.

Finally, although progressively, the use of smart or sensorised labels is gradually increasing, the integration of printed sensors, for example, for temperature monitoring to improve cold chain logistics, is still at the testing and development stage. Tracking temperature, reporting product deterioration and improving the consumer experience are the factors that will drive the incorporation of printed electronics into the field of intelligent packaging. On the other hand, the use of printed electronics in areas such as healthcare, for example by checking blister packs to see if medicine is being taken, is also a promising area.

Intelligent packaging is no longer desirable, it is inevitable. All studies suggest an increase in electronic printing in all sectors, including the packaging sector. Although its most widespread use is currently limited to promotional campaigns and consumer interaction, data acquisition through these applications will increase the information manufacturers/sellers have about their products, allowing them to improve and differentiate themselves. Also, the development of cost-effective anti-fraud solutions will allow brands to protect themselves from counterfeiting. Finally, the monitoring of temperature, the detection of possible contamination or the quality of products, the improvement of the consumer's experience, etc. are levers that will generalize the adoption of printed electronics in the packaging sector.

 

More information at https://www.itene.com/en/

 

 

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