After almost half a millennium of technological development, printing technologies have achieved a level to fulfill their mission: to satisfy the demands of a faithful human reception of the whole variety of shape and color from nature by discrete colored screen dots on substrates (e.g. paper, foil). Nowadays improvements of industrial printing are more or less solely limited to improvements of the production efficiency. During the last decade, several R&D and business approaches have been published which employ printing technologies for the production of items with functionalities other than color images. In case of these new applications, the major advantage of printing technologies is the full additivity of the material deposition addressing exactly the geometrical areas where it is needed – without lithography. Beyond that, the digital printing technique inkjet allows the handling of smallest amounts of rare (and therefore costly) functional materials. In our paper we introduce our strategy of functional printing that exploits the potential of cutting-edge printing technologies for the digital fabrication of items with advanced – i.e. “not only graphical” – functionalities. The presented examples comprise concepts for printed energy storage devices, packages with RFID functionality, printed membranes and micro sieves, electrically conducting tracks and outline further approaches to manufacture devices and components of organic and large-area electronics. The implementation of functional printing requires well-directed interdisciplinary efforts to manufacture stacks of functional layers and to understand their structure-property relationships. In many cases the envisaged functionality is directly related rather to the nanoscopic structures than to bulk materials properties. We introduce the integrated research approach of Printed Functionalities in Chemnitz comprising Chemnitz University of Technology for science, the Fraunhofer Institution for Electronic Nanosystems (FhG ENAS) for applied science and industrialization as well as world-class companies on the Chemnitz Smart Systems Campus for the exploitation of future organic and large-area electronics products.

Microsieves are permeable membranes with excellent properties for filtration applications. In this thesis the inkjet-technology is applied (1) to manufacture micro-porous microsieves, and (2) to reinforce the mechanical stability of float-cast, nano-porous microsieves: (1) The current process for inkjet-printed microsieves includes a manual step which is substituted by inkjet printing in order to increase the level of automation. The obtained microsieves are characterized regarding the pore size distribution. Effects which occur during the manufacture and broaden the pore size distribution are identified. Based on the results, the process is improved to obtain fully inkjet-printed microsieves with a narrowed pore size distribution. (2) The mechanical stability of fragile, float-cast microsieves is improved by the application of inkjet-printed reinforcement patterns on top of the microsieves. A machine is built to combine both technologies of float-casting and inkjet printing. The printing process is improved to manufacture reinforcement patterns of well-defined geometry. / Mikrosiebe sind permeable Membranen mit herausragenden Eigenschaften für die Anwendung in der Filtration. In der vorliegenden Dissertation wird die Inkjet-Drucktechnologie angewandt, um (1) mikroporöse Mikrosiebe herzustellen und (2) nanoporöse Mikrosiebe mechanisch zu stabilisieren: (1) Die Herstellung von Mikrosieben mittels Inkjet-Druck beinhaltet momentan einen manuellen Schritt, der durch einen Inkjet-Druckschritt ersetzt wird, um den Automatisierungsgrad des Verfahrens zu erhöhen. Die Mikrosiebe werden bezüglich der Porengrößenverteilung untersucht. Auftretende Effekte, die die Porengrößenverteilung verbreitern, werden identifiziert. Aus den Resultaten dieser Analyse wird der Prozess optimiert, um Mikrosiebe mit einer engen Porengrößenverteilung herzustellen. (2) Die mechanische Stabilität von fragilen Mikrosieben, die mittels Float-Casting hergestellt werden, wird durch das Aufbringen einer Stützstruktur mittels Inkjet-Druck verstärkt. Ein Maschinensetup wird aufgebaut um beide Technologien des Float-Castings und des Inkjet-Drucks zu kombinieren. Weiterhin wird der Prozess dahingehend optimiert, Stützstrukturen mit wohl-definierten Parametern zu erzielen.

After almost half a millennium of technological development, printing technologies have achieved a level to fulfill their mission: to satisfy the demands of a faithful human reception of the whole variety of shape and color from nature by discrete colored screen dots on substrates (e.g. paper, foil). Nowadays improvements of industrial printing are more or less solely limited to improvements of the production efficiency. During the last decade, several R&D and business approaches have been published which employ printing technologies for the production of items with functionalities other than color images. In case of these new applications, the major advantage of printing technologies is the full additivity of the material deposition addressing exactly the geometrical areas where it is needed – without lithography. Beyond that, the digital printing technique inkjet allows the handling of smallest amounts of rare (and therefore costly) functional materials. In our paper we introduce our strategy of functional printing that exploits the potential of cutting-edge printing technologies for the digital fabrication of items with advanced – i.e. “not only graphical” – functionalities. The presented examples comprise concepts for printed energy storage devices, packages with RFID functionality, printed membranes and micro sieves, electrically conducting tracks and outline further approaches to manufacture devices and components of organic and large-area electronics. The implementation of functional printing requires well-directed interdisciplinary efforts to manufacture stacks of functional layers and to understand their structure-property relationships. In many cases the envisaged functionality is directly related rather to the nanoscopic structures than to bulk materials properties. We introduce the integrated research approach of Printed Functionalities in Chemnitz comprising Chemnitz University of Technology for science, the Fraunhofer Institution for Electronic Nanosystems (FhG ENAS) for applied science and industrialization as well as world-class companies on the Chemnitz Smart Systems Campus for the exploitation of future organic and large-area electronics products.

Microsieves are permeable membranes with excellent properties for filtration applications. In this thesis the inkjet-technology is applied (1) to manufacture micro-porous microsieves, and (2) to reinforce the mechanical stability of float-cast, nano-porous microsieves: (1) The current process for inkjet-printed microsieves includes a manual step which is substituted by inkjet printing in order to increase the level of automation. The obtained microsieves are characterized regarding the pore size distribution. Effects which occur during the manufacture and broaden the pore size distribution are identified. Based on the results, the process is improved to obtain fully inkjet-printed microsieves with a narrowed pore size distribution. (2) The mechanical stability of fragile, float-cast microsieves is improved by the application of inkjet-printed reinforcement patterns on top of the microsieves. A machine is built to combine both technologies of float-casting and inkjet printing. The printing process is improved to manufacture reinforcement patterns of well-defined geometry. / Mikrosiebe sind permeable Membranen mit herausragenden Eigenschaften für die Anwendung in der Filtration. In der vorliegenden Dissertation wird die Inkjet-Drucktechnologie angewandt, um (1) mikroporöse Mikrosiebe herzustellen und (2) nanoporöse Mikrosiebe mechanisch zu stabilisieren: (1) Die Herstellung von Mikrosieben mittels Inkjet-Druck beinhaltet momentan einen manuellen Schritt, der durch einen Inkjet-Druckschritt ersetzt wird, um den Automatisierungsgrad des Verfahrens zu erhöhen. Die Mikrosiebe werden bezüglich der Porengrößenverteilung untersucht. Auftretende Effekte, die die Porengrößenverteilung verbreitern, werden identifiziert. Aus den Resultaten dieser Analyse wird der Prozess optimiert, um Mikrosiebe mit einer engen Porengrößenverteilung herzustellen. (2) Die mechanische Stabilität von fragilen Mikrosieben, die mittels Float-Casting hergestellt werden, wird durch das Aufbringen einer Stützstruktur mittels Inkjet-Druck verstärkt. Ein Maschinensetup wird aufgebaut um beide Technologien des Float-Castings und des Inkjet-Drucks zu kombinieren. Weiterhin wird der Prozess dahingehend optimiert, Stützstrukturen mit wohl-definierten Parametern zu erzielen.