Hybrid Printing for the Fabrication of Smart Sensors

We focus on the combination of 3D printed substrates and inkjet printing which is subject to vivid research. We believe that their combination can enable a complete and normal censor system concept in automated production lines in collaborative robotics. So the main advantage of this technique is its use of use.

While it's still assures a high quality of the obtained measurements. Which are gathered with the tele adoption system prototypes. When combining 3D and inkjet printing for functionalization.

It is important to consider the substrate properties as well as the ink properties for individual layers. Also, the curing dose depends on a combination of both. Fabricate the ceramic substrate by the lithography-based ceramic manufacturing technology.

To fabricate interconnects on on non-conductive substrates, dispense the low temperature, curable conductive adhesive, with a time pressure micro-dispenser mounted on a micro-assembly station into the appropriate vias of the printed parts. Leave the fabricated interconnects to dry for ten minutes at twenty three degrees Celsius and with ambient pressure. After preparation of the inkjet printing system and inspection of the surface properties for print ability as described in the text protocol.

Fix the substrate on the substrate table using adhesive tape and mark its position appropriately. Adjust the nozzle and printing parameters in the settings of the software interface by editing the properties of the print head in the printers software interface. Move the print head to the drop view position using the go to drop view position option in the printers software interface and observe the jetting of the ink.

If necessary adjust the printing parameters to optimize the jetting. Choose the nozzle which ejects well defined and homogeneous drops of ink for printing. Enter the number of the chosen nozzle in the printers preferences.

Perform the drop size tests to determine the size of one printed drop on the substrate to do so print a drop pattern using a known printer configuration. Determine the achieved drop size, using a calibrated microscope or the inbuilt camera system of the printer. Ensure that the subsequently used printing resolution is appropriate for the observed ink wetting to fabricate a homogeneous and closed surface.

Print multiple structures with a layer of ink used for the first device layer onto a dummy substrate. Use the photonic curing process for the insulating ink on the metal substrate. Open the tray of the photonic curing equipment containing the substrate table.

Move the sample to the substrate table of the photonic curing equipment and fix it accordingly. Adjust the height of the equipment substrate table using the table spindle to move the sample to the focus plane of the curing equipment. Close the tray, adjust the curing profile as recommended by the supplier for the printed material and the equipment software interface and press the start button.

Adjust the nozzle and printing parameters as described in the text protocol and then perform printing. Repeat the printing of one layer of ink until the homogeneity of the print is satisfactory. Control the homogeneity of the printed layer, using a calibrated microscope.

Or using the inbuilt camera system of the printer. Move the camera of the printer to the print position and observe the quality of the print given in the printer software interface. For silver ink on a ceramic substrate, use heat curing in an oven.

As recommended with the ink. To cure printed dye-electric ink use the photonic curing equipment with 200 volts bank voltage and with one millisecond pulses, and repeat the pulses eight times at a frequency of one hertz. Perform profilometer measurements to determine the roughness and thickness of the printed layer.

Put the sample on the substrate table of the profilometer. If not honed, hone the measurement head using the respective button in the software. Choose the resolution and area, which needs to be mapped.

Place the measurement head at the starting position and start the measurement. Upon completion of the measurement, check the result for consistency, and save the data. After adjustment of the printer and curing parameters, for subsequent layers as described in the text protocol.

Fix the sustrate on the substrate table at the previously marked position. Adjust the nozzle and printing parameters as before. Select the appropriate reference point to print the pattern, and make sure the printed patterns are well aligned with each other to ensure proper functionality of the device afterward.

Load the respective SVG file with appropriate resolution and size. Perform printing. Repeat the peintin of one layer of ink until the homogeneity of the print is satisfactory.

Control the homogeneity of the printed layer under a microscope. Here, the inbuilt camera system of the printer is used. Use photonic curing only for the curing of this layer.

Use the parameters determined beforehand, for an insulating layer or a conductive layer on the insulator. After curing, control the electircal and structural properties of the printed layer. To determine if the conductivity range of the conductive layer is acceptable, use a multimitor.

To determine the surface quality of the 3D printed substrates. Scanning electron microscopy analysis are done. The surface of the copper substrate is shown, which is by far the smoothest.

Conversely, steel as a substrate that is not usable for ink jet printing, due to the high porosity and unstable contact angle. Also, shown are SEM images of the bronze substrate and the titanium sample surface. The conductive tracts on the aluminum based ceramic substrate have good surface homogeneity.

As visualized here as the smoothness of the blue curves. Additionally, surfaces which loss their structural integrity can be identified by the large gradients in their height profiles. These measurement results are gathered using a demonstrator, which employs a capacitative sensing principal.

Here, the smoothness of the curves illustrates the high achievable quality despite the structural deficiencies that might result from the printing processes. The most crucial steps are to assure sufficient homogeneity and to control the surface properties of the printed structures. These metrics are crucial enabling factors for subsequent steps.

The combination of 3D printed substrates and inkjet printing as means for functionalization are of high important starts the development of future robotic devices and automated production. These techniques enable the fabrication of adaptable sensor systems to be used for retrofitting and in conformable systems. Which are considered the future of collaborative robotics.