Try to dilute your ink using a solvent.

Hi Dr. Xuhua Wang

Thanks for your suggestion. I already diluted the ink, it contains surfactants and polymers to meet the viscosity and surface tension requirement. I was wondering if there is other parameters that I might need to consider.

Adding some dopants which are different from your solvent. You could search it from the patent applications to know what dopant could be the best for your inks.

I had a similar problem with a PEDOT:PSS-ink. This conductive Polymer was dissolved with water. There were three aspects to provide the printablitiy.

1. Increasing the amount of the solvent (in this case water), but this comes with the necessity of printing more layers, because of the decreased particle conzentration.

2. Increasing of the cartridge temperatur and as a result of that decreasing the viscosity. Be careful with that, because it can also trigger the drying/clogging of your ink in the nozzles, especially when there are longer breaks between printing.

3. The most promising thing you can do is to adjust your waveform. Increasing the slew rate of the voltage pulse could solve your problem.

Another thing which is an anytime troubleshooting for inkjet printing is to run several cleaning cycles, especially when you insert a new cartridge.

Also always store your cartridges in a humid environment.

I hope, maybe something of that will help you!

Hi Robin Kaufhold

Thank you very much for your detailed explanation. I tried increasing the temperature to reduce the viscosity, but that didn't work. I also tried adjusting the printing parameters (slew rate etc.), it didn't work out either. I also try cleaning the nozzles via purging several times for 1sec. However, may be it the nanoparticle partially clogging the nozzles, thus hindering the deposition. But I don't get one thing, if it was blocked, then noting would have come out, but in my case, it's pulsating from the nozzles (droplets showing up at the nozzles and being drawn inside and repeats the process). I am wondering if it's partial clogging or viscosity/surface tension or need waveform adjustment.... Do you have any suggestion on this? Thanks again.

Hi Touhid Bin Anwar

The information with the cleaning cycles was only additional as a general advice for inkjet printing problems. I also don't think that your nozzles are clogged, when you can see the pulses of the ink in the drop watcher.

I suggest that the parameters of your ink (viscosity/surface tension) are not suitable.

There are 2 different ways, how you can solve your problem:

1. adjust your printing parameters:

waveform (higher slew rate, shorter segment duration)

temperatur (higher)

nozzle voltage (higher)

2.adjust your ink:

adding a solvent with a lower vicosity as Xuhua Wang said or further dissolve your ink with the given solvent (depends on the solvent of your ink)

That are all possibilities I am aware of.

Please let me know, when you solved your problem.

Best regards,

Robin