Towards the Upscaling of Electrohydrodynamic Printing
The SCRONA printer facilitates the upscaling of electrohydrodynamic (EHD) printing and, hence, its use for industrial applications. The multi-nozzle system accelerates the printing process and even enables multi-material printing. The SCRONA technology allows (additive) micromanufacturing with a resolution of about 1 µm.
Electrohydrodynamic Printing EHD printing is of emerging interest for the manufacturing of, e.g., electronic devices and sensors. By applying an electric field between an ink-holding nozzle and a substrate, the ink gets pulled to-wards the substrate where it deposits. This way, EHD printing can offer printing resolutions of 20 nm. To maintain the electric field that is required for printing, the distance between the tip of the nozzle and the substrate is usually only 10 µm.
Advantages of SCRONA For industrial applications, a greater distance between nozzle and substrate is desired. Moreover, for a potential upscaling, the printing process needs to be accelerated. The SCRONA printer achieves both. By applying the electric field between the nozzle and an aperture, the distance to the substrate is increased to 1 mm. To accelerate the printing process, the print head can feature up to 1000 printing nozzles that can be individually controlled. Each print head is micromanufactured as a single MEMS-Chip, allowing a straightforward application.
The SCRONA printer allows direct patterning of three-dimensional microstructures. This is a major advantage over, e.g., lithography, where the patterning is done chemically after the actual printing process. A wide range of materials can be printed with SCRONA (e.g., molecule/salt solutions, proteins, microparticles, waxes …) resulting in printed structures of any desired functionality. Promising applications include functional displays, semiconductor packaging and micro-optics.
Micro/Nano-Optics at Empa
The SCRONA printer is hosted at Empa by the Transport at Nanoscale Interfaces Laboratory. The research group Nanoelectronics and Nano-Optics uses the printer to explore the micromanufacturing of photodetectors. They want to demonstrate the functionality of photonic devices printed with novel inks and unusual architectures (e.g., photodetectors printed on fibers). For this, they work closely together with the Functional Inorganic Materials Laboratory at ETH Zurich that synthesizes functional inks.