Industrial-strength Inkjet Technology

 
The basic building block of Xaar’s drop-on-demand printheads is the piezoelectric actuator. This is a MEMS (micro electro-mechanical system) component made of a piezoelectric ceramic. Depending on the printhead size and form each actuator contains a number (e.g. 128, 382, 500) of very narrow (e.g. 70um) channels that are filled with ink. In an ‘End-Shooter’ device at the end of each channel is a small hole through which the ink is ejected. In a ‘Side-Shooter’ device the nozzle or hole is made in the side (bottom) of the channel.

The driving force that ejects the drop comes from a very rapid deflection of the channel side walls (up to 120 kHz) which creates an acoustic wave that travels down the channel and ejects a drop as it reaches the nozzle-plate. The way the piezoelectric material is used is called shear-mode because of how it deforms when a voltage is applied.

The acoustic wave method of drop formation means there is almost no mechanical stress on the material of the actuator. This in turn means two things:

1. Extremely high life-time – each channel can be actuated billions of times without failing. In laboratory tests we have exceeded 10¹³ actuations and found no failure mode making this the ideal technology for heavy duty industrial print applications.
2. Very low power consumption – again as it is not a mechanical push the actuator uses relatively little energy and can be driven with much lower voltages. In industrial printing machines this has a positive impact in minimising total energy consumption.