Droplet property optimization in printable electronics fabrication using root system growth algorithm

Abstract For printable electronics fabrication, the printing quality delivered by a Drop-on-Demand (DoD) Piezoelectric Inkjet (PIJ) Printhead is limited due to the residual vibration problem in the ink channel. The residual vibration after jetting the ink drop influences the droplet velocity and volume consistency, and limits the maximum jetting frequency of the printhead. In order to meet the challenging requirements of printable electronics fabrication, this work proposes a novel Optimization framework for optimal parameter setting of the high-frequency driving waveform. A novel Root System Growth Algorithm (RSGA), based on principles from plant root growth and foraging behaviors, is chosen as the core optimization algorithm of the framework. The proposed RSGA is benchmarked against other four state-of-the-art bio-inspired algorithms using CEC2005 test function suite. Then several groups of experiment results for various targets are presented to demonstrate the universality of the proposed optimization-based search system for the improvement of printing quality. Simulation results show that the RSGA has an outstanding performance in searching the driving waveform parameters for specified droplet properties.