Damage to plastic packaging material can be fairly easily detected with the use of test strips. The immersive oxygen due to the package leakage causes a chemical reaction which discolors the test strips. This procedure is, however, only suitable for use in food retailing, with certain reservations. Considering that the discoloration is observable by the customer it might tend to harm the retailer’s image.

Researchers at the Center for Printed Intelligence (CPI) of the VTT Technical Research Centre of Finland have developed an electronic spoilage sensor concept for poultry. The core of the concept is a resistance sensor which can be inkjet printed onto the packaging material. The sensor’s resistivity changes, when it is exposed to the fermentation gas hydrogen sulfide (H2S). Resistivity variance can be measured, using a wireless reading device that detects even the slightest change in H2S concentration. CPI Director Harri Kopola explains the advantages of this technology concept: “The retailer can remove damaged packages from shelves before the merchandise spoils and customers take it home.”

On the other hand, the cardboard box “HighLight” is specifically designed to attract customers’ attention. The packaging manufacturer Karl Knauer in Bieberach, Germany was the first to apply a display over more than one side of a box – even on curved surfaces – on the basis of printed electronics. This display functions with the optical phenomenon of electroluminescence to shine in different colors and to depict logos, images and texts.

It can be additionally equipped with a motion sensor, causing it to blink when a potential customer is approaching. This function can provide a decisive competitive edge at point of sale. The “Deutsche Verpackungsinstitut e.V.” (a German packaging association) awarded the Karl Knauer KG the “Deutscher Verpackungspreis 2008“ (German Packaging Prize 2008).
Heading Toward Smart Packaging

In the future, however, packaging should offer many more functions. Manufacturers are now developing “Smart Packages” that can:

* Provide additional information in various languages
* Read product inserts to the visually impaired
* Inform patients of product interactions with other drugs
* Ensure product authenticity through integration of fraud resistant electronic codes
* Signal when the expiration date of a food product is reached or the cold chain has been interrupted.
* Provide power for all electronic components through solar cells and batteries printed directly onto the package

Organic and printed electronics play an important role in the realization of these additional functions. They enable the printing of electronic components such as RFID transponders, photovoltaic cells or light-emitting diodes with plastics, so-called “polymers” onto a light, flexible substrate. As polymers are liquid-soluble and, depending upon their chemical composition, have insulating, semi-conductive or conductive properties, they are suitable for the cost-effective production of electronic components in continuous printing processes (see background information).”Organic and printed electronics offer completely new packaging functions to improve user-friendliness and increase marketing advantages” says Martina Claus, Coordinator of Technology and Development at COPACO Gesellschaft für Verpackungen mbH & Co. KG in Mainz, Germany.

The COPACO Group is a member of the Organic Electronics Association (OE-A) – a working group within the German Engineering Federation (VDMA). The OE-A has more than 120 member companies, and represents the whole value chain of the organic and printed electronics industry. Furthermore, COPACO has applied to the German Federal Ministry of Education and Research (BMBF) for a research project with companies such as Merck, BASF and SAP, which should trigger strong incentives for the packaging industry. “Goal of the project”, says Claus, “is the development of new organic materials and manufacturing procedures for organic and printed circuits with additional elements such as sensors, data storage units or displays for applications in the fields of packaging and textiles.
LOPE-C Displays Trends and Technologies

Further trends on “organic and printed electronics” will be on display at the LOPE-C Large-area, Organic & Printed Electronics Convention which will take place as a conference with an accompanying exhibition at the Congress Center, Messe Frankfurt from June 23-25, 2009. Upon invitation by the OE-A (Organic Electronics Association) experts from business and research will convene at this world premiere to exchange knowledge and ideas on opportunities, products and developments in the field of organic and printed electronics.