Structuring of Magnetic Nanoparticle Fluids for Decorative and Functional Printing and Coating

Printing and coating of magnetic inks is widely used in the field of magnetic barcode labels. Nanoparticle inks have gained increasing interest in the field of printed electronics. Controlling the transport of magnetic nanoparticle fluids by external magnetic fields is nowadays mainly applied in environmental and biomedical research, e.g. in order to transport functionalised magnetic particles for drug delivery, sensing, thermal cancer therapy, or for the extraction of pollutants in waste water cleaning. Application examples of field assisted nanoparticle assembly or fluid control in coating and printing, e.g. for the structural colour generation in photonics, are recently emerging. In this paper, we address the topic of field assisted patterning by the design of a versatile magnetic pattering and structuring platform for field assisted nanoparticle assembly and locally tailored pattern formation in printing and thin film coating. 2D finite element modelling for tailored magnetic field patterning, as well as experimental inkjet printing and coating results for Fe
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O
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iron oxide nanoparticles on glass are presented and discussed. The developed print patterning technique is of interest for decorative and functional printing and coating, e.g. for further developments in the application field of smart security tags.