Low-cost oxygen dose indicator tags for leak and tampering indication
Abstract
A Swedish research institute has developed a method for printing oxygen dose indicators in a standard reel-to-reel printer. Non-hazardous materials are used, and physical property changes, due to oxygen exposure, can be detected remotely. This feature is unique.
The institute is seeking users and providers of solutions for modified atmosphere packaging and tamper proofing, for further study and development of the oxygen indicators. It intends to offer a pre-study project on the indicator tags.
Description
The Swedish research institute is active in developing printed electronic devices. Focus is mainly on electrochemical devices, such as displays and transistors. Priorities are placed on extremely low production costs, manufacturing safety, as well as use and disposal of the devices, since the products are intended for large volumes and wide spread use.
During this work, a method for printing oxygen dose indicator tags in a standard reel-to-reel printing machine has evolved. Key features with these indicators are that harmless and non-migrating materials are used, and that oxygen exposure results in not only a clear color change, but also in significant changes in electrical properties, that can be detected remotely. The latter feature is unique, compared to what is known in the prior art, and paves way for efficient screening of e g defect food packaging.
A pre-study project is proposed, in which further development of the indicator tags for RFID (Radio Frequency Identification) purposes will be the main aim (see "Further Information" below).
Innovative Aspects:
The technology enables:
" Remote reading of oxygen dose indicator tags
" Low cost manufacturing, reel-to-reel printing
" Use of harmless compounds
Materials:
The materials used are approved as food additives or for food contact. The electrode material is non-migrating, and consists of organic materials only. It is also possible to seal. These features enhance the possibility of obtaining governmental approval for food contact applications of devices where this material is encapsulated.
Indicator properties:
Indicator strips manufactured so far exhibit a three fold increase in the value of a measurable electrical property.
The tags can be handled in air for a few minutes without any notable change in optical and electrical properties. This enables facile handling during manufacturing and during use in packaging applications.
Activation of the tags can either be done in-line in the printing machine, prior to storing in inert gas, or later, after the tag has been sealed in an oxygen-free atmosphere.
