Enhanced Liquid Metal Micro Droplet Generation by Pneumatic Actuation Based on the StarJet Method

We present a novel pneumatic actuation system for generation of liquid metal droplets according to the so-called StarJet method. In contrast to our previous work [1, 2], the performance of the device has been significantly improved: The maximum droplet generation frequency in continuous-mode has been increased to fmax_=_11 kHz (formerly fmax_=_4 kHz). In addition, the droplet diameter has been reduced to 60 μm by a new design of the star shaped nozzle made from silicon by MEMS technology. The size of the metal reservoir has been increased to hold up to 22_mL liquid metal and the performance and durability of the actuator has been improved by using stainless steel and a second pneumatic connection. Experimental results are presented regarding the characterization of the droplet generation as well as printed metal structures.