Electrostatic inkjet printing of carbon nanotube for cold cathode application

We demonstrate the printing of carbon nanotube (CNT) solution using the electrostatic inkjet nozzle and the field emission from the printed CNT. The CNT solution was prepared from the water-soluble single-wall CNT. An electrostatic inkjet nozzle having a needle inside a capillary was built in-house, which was able to eject droplets according to the applied electric pulse voltage. We found that the liquid can be ejected from the needle apex by increasing the wettability of the liquid. The printed dot size of the liquid was reduced by increasing the viscosity of the liquid and by decreasing the applied voltage. The field emission current obtained from the printed CNT was approximately 8 μA for the emission area of approximately 3 mm².