From solar PV to wearables – digital printing technologies are booming

Interview with Alan Hodgson, Chair, Technical Committee 119: Printed electronics

By Antoinette Price

Alan Hodgson participated in several sessions during the Printing for Fabrication conference organized by the Society for Imaging Science and Technology (IS&T) in Dresden, Germany, in September.

runner in sensoria smart clothing Electronics can be printed onto flexible layers making them ideal for smart wearables (Photo: Sensoria Inc.)

Since printing brings together the printed electronics, wearables and display communities, such events allow participants from a broad industrial, academic and engineering background the chance to discuss and develop better solutions for healthcare and clothing. IEC has already produced International Standards relevant to these areas, which include inkjet printing measurement, substrates for wearables and surface roughness.

E-tech caught up with Hodgson to learn about the topics discussed and the useful feedback he received on future areas for standardization.

Why is this event important for IEC?

“The conference Printing for Fabrication explores the potential applications of digital printing technologies in areas for which IEC carries out standardization activities, such as photovoltaics and lighting devices.

For instance, using the new thin-film technologies, photovoltaics electronic assemblies can be produced on flexible substrates, allowing new design freedoms. This means printing techniques for manufacturing electronics assemblies becomes an attractive prospect, because these techniques allow industry to fabricate diverse devices and structures and because printing processes are also amenable to roll-to-roll processing, in which electronic devices are created on a roll of flexible plastic or metal foil. Printing will also allow photovoltaics to be incorporated into other electronics systems, such as photovoltaics for energy harvesting at low light levels. The conference also looked at the potential for using printing to fabricate electronic components that will be integrated with other electrotechnical components to produce a physical manufactured product, such as electronic displays and printable materials for organic light-emitting diode (OLED) luminants.
 
Moreover, printed electronics have a role to play in the manufacture of future wearable electronic devices. Electronics can be printed onto textile flexible and/or stretchable substrates, thus becoming flexible displays that can be integrated into garments. These could then be incorporated into wearable devices that could fit into everyday life in a variety of implementations.

Several IEC Technical Committees (TCs) publish International Standards for printed electronics and digital printing technologies, which will help develop and hasten many products to market, such as wearables for healthcare and clothing and more.”

What topics were discussed?

The conference dealt with the use of printing for the fabrication of components, such as sensors and microelectromechanical systems (MEMS) devices.

“On the topic of sensors, it was about the ability to combine the printing on both electronics and sensor elements, plus all the different materials and production processes that can be deployed for sensor fabrication. For MEMS devices, discussions covered the use of printing techniques related to certain aspects of the electrical connections between the multi-layered assemblies. There was also a strong component of inkjet printing technology. The delegates working in that area have become interested in the work of IEC TC 119, in particular, the IEC 62899-302-1 and 2 International Standards which cover the imaging based measurement of jetting speed and droplet volume for inkjet equipment, respectively.”

With the printed electronics, wearables and display community in attendance, it is the ideal opportunity to explore the technical issues around the fabrication of textile electronics and sensor assemblies and examine where these devices fit into the IEC interest areas, including smart cities, industry 4.0 and active assisted living (AAL). 

“In terms of technical issues, we concentrated on those areas not already covered by IEC TC 119 and IEC TC 124 for wearable electronic devices and technologies. Broadly speaking these are sustainability, 3D printing, electrostatics, barrier layers and surface roughness. For smart cities, it is the issue of ‘citizen as a sensor’ through wearable electronics. In other words, citizens become mobile sensor platforms, feeding actionable data back into the infrastructure of the Smart Cities of the future. Since the meeting was held in Germany, there was a big focus on industry 4.0 and where textile electronics fit into the factory of the future. In relation to AAL, increasingly sensors and printed electronics are being integrated into smart wearable devices to facilitate the healthcare and well-being of ageing populations.”

Showcasing IEC work

During the conference, a session was devoted to International Standards and intellectual property.  

Hodgson presented his paper entitled International Standards Enabling Printed Electronics for Wearables, which introduces the standardization effort taking place to support the industrialization of wearable electronic devices and where printing for fabrication technologies will fit into these. It covers market sectors for wearable electronic devices and examines where printed electronics and other technologies will contribute, concentrating in particular on textile electronics and sensor fabrication. It also explains the concept of e-textiles in this space and explains how interested parties can participate and the benefits thereof.

IEC TC 119 expert Kei Hyodo presented the Overview of Standardization Activities for Inkjet Additive Manufacturing (within IEC TC 119 Printed Electronics). The paper explains that until recently, inkjet printing technologies have been mainly applied to conventional graphics printing and as such didn’t require standardized evaluation methods. However, the advent of additive manufacturing and expansion of printed electronics, in particular has brought about an industry-wide need for standard evaluation methods of this type of printing, which IEC TC 119 is addressing.

What are some of the challenges?  

There is still much work to do and new areas that need to be addressed.

“In terms of the future areas requiring standardization, we discussed the topic of sustainability and the congruence of this approach through the UN Sustainable Development Goal 12, which aims to ensure responsible consumption and production. The integration of printed electronics into 3D printed structures was raised and specific issues around electrostatics, data privacy and terminology were also mentioned. As this was a technical audience, it also proved to be a good opportunity to explore some of the more complex areas for future work such as flexible barrier layers, functional textiles and the effects from surface roughness and structure.”

The results of this feedback will be included in a review of the IEC TC 119 strategic business plan, during the IEC General Meeting in Busan, Korea in October.

Future events

The conference was very positive because it allowed IEC participants to specifically target pertinent disciplines with a message about the importance of IEC Standards, and discuss what work is in the pipeline.

Hodgson plans to discuss data security and privacy issues of mobile devices during the upcoming IS&T Colour and Imaging conference in Vancouver, Canada. This is an area of common interest between IEC TC 124 and the IEC and ISO Joint Technical Committee for information technology, (ISO/IEC JTC1), which covers many topics including biometrics and IT security.

“From a TC 124 perspective it is the personal medical and well-being data that will flow from the wearable into the mobile device. The Colour and Imaging conference is more concerned with the acquisition of biometric and identity data. As these all come together, there is the issue of consumer trust in mobile platform security, cyber and physical. This is what I plan to explore at this conference and I believe International Standards could make a significant contribution.”

Gallery
Electrode structures printed on flexible materials The honeycomb-shaped electrode structures are printed on 3D-Micromac´s microFLEX™ platform by flexo printing. The cu-containing ink was used to achieve high conductivity. After printing, the ink was dried and cured (Photo: 3D-MICROMAC)
runner in sensoria smart clothing Electronics can be printed onto flexible layers making them ideal for smart wearables (Photo: Sensoria Inc.)