Final Activity Report Summary - PRINCIPLE (Printing concepts for innovative patterning of low-cost electronics with (sub)micron resolution)
The project investigated functional materials devices made by the so-called additive methods. The deposition of thin films of functional materials was investigated and devices made of such materials were studied.
Current manufacturing processes for thin-film devices are mostly based on photolithographic processes. These processes have good resolution, nevertheless they waste, at the same time, most materials that are used and need many process steps, namely sheet deposition of metal and resist, exposure, development, etching and stripping. Moreover, some new materials such as light-emitting polymers do not withstand all process steps. These cost and environmental considerations introduce the need for new cost-effective patterning methods that do not waste material. In this project additive methods were used and investigated, namely inkjet printing and electrospraying, and the produced devices were characterised and tested.
Via inkjet printing organic light-emitting diodes were produced. Blue-emitting polymer layers were created and the electronic properties were determined and compared to spin-coated devices. The current-voltage characteristics of both types of devices were very similar, indicating the high degree of control of the inkjet printing process. In further studies the light outcoupling distribution was determined from angular, wavelength and polarisation resolved emission experiments, combined with modelling.
Another additive thin-film deposition method was studied, namely single event electrospraying (SEE). The goal was to investigate the stability regime for electrospraying events in order to be able to accomplish an on-demand small-volume deposition technology. Fluid dynamics during the voltage pulse were studied in order to understand relaxation times, voltage behaviour, volume behaviour and stability. Capillaries of different sizes with different coatings were tested. A stable and short event of jetting or droplet formation for each applied voltage pulse was generated, down to deposition volumes of less than 10 pL per voltage pulse.
Thin-film deposited dry-reagent layers were prepared on a substrate with biological materials, in order to investigate a rapid thin-film biosensor. The biosensor was based on a competitive immunoassay with detection and manipulation of magnetic nanoparticles. Experiments on the deposition process, drying process and drying buffer components were systematically performed in order to enable good redispersion, reproducibility and specificity. This resulted in a successful demonstration of a one-step morphine competitive immunoassay using the thin-film biosensor concept, giving assay results in less than one minute.
Current manufacturing processes for thin-film devices are mostly based on photolithographic processes. These processes have good resolution, nevertheless they waste, at the same time, most materials that are used and need many process steps, namely sheet deposition of metal and resist, exposure, development, etching and stripping. Moreover, some new materials such as light-emitting polymers do not withstand all process steps. These cost and environmental considerations introduce the need for new cost-effective patterning methods that do not waste material. In this project additive methods were used and investigated, namely inkjet printing and electrospraying, and the produced devices were characterised and tested.
Via inkjet printing organic light-emitting diodes were produced. Blue-emitting polymer layers were created and the electronic properties were determined and compared to spin-coated devices. The current-voltage characteristics of both types of devices were very similar, indicating the high degree of control of the inkjet printing process. In further studies the light outcoupling distribution was determined from angular, wavelength and polarisation resolved emission experiments, combined with modelling.
Another additive thin-film deposition method was studied, namely single event electrospraying (SEE). The goal was to investigate the stability regime for electrospraying events in order to be able to accomplish an on-demand small-volume deposition technology. Fluid dynamics during the voltage pulse were studied in order to understand relaxation times, voltage behaviour, volume behaviour and stability. Capillaries of different sizes with different coatings were tested. A stable and short event of jetting or droplet formation for each applied voltage pulse was generated, down to deposition volumes of less than 10 pL per voltage pulse.
Thin-film deposited dry-reagent layers were prepared on a substrate with biological materials, in order to investigate a rapid thin-film biosensor. The biosensor was based on a competitive immunoassay with detection and manipulation of magnetic nanoparticles. Experiments on the deposition process, drying process and drying buffer components were systematically performed in order to enable good redispersion, reproducibility and specificity. This resulted in a successful demonstration of a one-step morphine competitive immunoassay using the thin-film biosensor concept, giving assay results in less than one minute.