Electrically readable indicators

M. Allen, A. Alastalo, T. Varpula, T. Riekkinen, S. Jussila

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional


The focuses on "electrically readable indicator" sub-projects have been on the development of printable conductive wiring and electrical thin film indicators. The research work conducted in the first project involved ink-jet printing of conductive wiring using nanoparticle ink, the development of a wireless humidity sensor with polyvinyl alcohol acting as the sensing element and the fabrication and measurement of oxygen deficient titanium dioxide thin-films for room-temperature oxygen sensors. Printing and curing multiple layers led to high enough conductivity for printing functioning RF-coils. A reduction in Q-value of approximately 15% was witnessed between 50% and 100% relative humidity for the wireless humidity sensor and the TiO2-? oxygen sensors showed ~15% relative change in conductivity at room temperature when illuminated with UV. The research under the subtitle 'Electrical thin film indicators' (2005-2006) was focused on studying such oxygen sensitive materials that involved a change of conductivity rather than a change of color as a function of oxygen exposure. The studied materials were both reactive metallic thin films and organic based thin films and their suitability for food packages was a prerequisite for the utilization. In the beginning of the project a literature survey was made to find out which metals would be the best candidates for oxygen detectors (Ylilammi 2005).
Original languageEnglish
Title of host publicationIntelligent Products and Systems
Subtitle of host publicationTechnology theme - Final report
EditorsOlli Ventä
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages14
ISBN (Electronic)978-951-38-7010-2
ISBN (Print)978-951-38-7009-6
Publication statusPublished - 2007
MoE publication typeD2 Article in professional manuals or guides or professional information systems or text book material

Publication series

SeriesVTT Publications

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