by Peter Buttiens, ESMA

Bacterial cellulose nanopaper for biosensing applicationsBacterial cellulose nanopaper for biosensing applicationsWhen talking about such an extremely broad concept as “functional printing” we should probably start with a short history lesson. In its early days, the functional printing relied on chromatic inks which changed colour due to external influences such as light (UV/black light), temperature (heat), pH changes or water contact. They found their applications in printed gadgets, especially packaging which took marketing advantage from the distinctive special effects. The glowing and phosphorescent decoration started years ago and reappears on the market on continuous basis. More advanced and more functional opportunities have followed and entered new industries. Evolution in conductive inks and electroluminescence (EL) not only benefited branding purposes (e.g. light-emitting packaging of Bombay Sapphire Gin) but delivered solutions also for solar panels (fingers and busbars).

Initial applications have pushed the boundaries of functional printing. Printed circuit boards (PCB) and flexible antennas combining FM, TV, mobile, GPS in one antenna and used e.g. in automotive,  gave rise to car radar systems for adaptive cruise control. Nowadays, near field communication (NFC) and RFID antennas are standard features in electric devices and the integration of printing in the manufacturing process constantly improves their cost-efficiency. As far as electroluminescence is considered, a technological jump took place towards OLED (organic light emitting diodes). Flexible OLEDs integrated in fabric pave the way for smart textiles and wearables, as shown in one of the recent ESMA-powered international projects – POLEOT (Printing of Light Emitting Devices on Textile).

Bulb less lamp LE printed directly onto textileBulb-less lamp - LE printed directly onto textile (POLEOT project)The door to the future of printed electronics, conductive inks and coatings is now wide open. Batteries (flexible, thin, rechargeable), energy harvest systems (based on Peltier effect), smart tags and sensors are becoming common consumable goods, many of them disposable, too. Smart wearables and smart sensors increasingly find applications in medical and pharmaceutical sectors, for instance quick test strips for diabetics, blood analysers, smart blister packs… Healthcare is one of the markets which embrace new solutions and enable successful business cases of printers who decided to “go functional”. Quad Industries has developed temperature logger labels for blood bags used in transport. The smart tag registers and transmits data to a smartphone app to ensure the correct transport conditions.

When mentioning the smartphone, many may not realise the number of its components facilitated by printing techniques. Capacitive switches, batteries, touch panels and screens – printing once again replaces expensive and highly energy-consuming processes. Obviously, marketing departments will come on board, as well. One of the recent Audi TT brochures included printed controls which, after aligning with the smartphone on the right spot, turned the page into a controllable experience of the new model’s cockpit display.

Functional printing partners with anti-counterfeiting technologies and delivers combinations of inks, coatings and substrates to create invisible markers. Both for monetary needs or luxury goods, security print is the most efficient and cost-attractive protection against imitation. Current possibilities offer even fingerprint recognition surfaces.

Many of the above mentioned applications are included in the in-mould decoration process, be it for automotive or electronic devices – ranging from the integration of antennas in car mirror caps, in the car console, to capacitive buttons on 3D thermoformed parts and surfaces. The industry is growing and gives new, creative development dimensions for printers, manufacturers and product designers. They will all meet for 19 technical talks and business cases presented during the 3rd Advanced Functional and Industrial Printing conference.