Comprehensive study on electrospray deposition in the single Taylor cone-jet mode by changing the spatial electric potential using a ring-shaped ternary electrode

Abstract

In this work, the effect of changing the spatial electric potential to the spray current and the threshold voltage in the single Taylor cone-jet mode of the electrospray deposition (ESD) process has been investigated. The spatial electric potential between a nozzle electrode and a counter electrode was deformed by using an additional ring-shaped ternary electrode. The voltage ranges of the stable single Taylor cone-jet were determined from the current-voltage (I-V) characteristics of the system. Depending on the changes occurring in the spatial electric potential around the nozzle electrode, a shift of the threshold voltage to form a stable single Taylor cone-jet was clearly observed. For further investigation, the spatial electric potential and electric-field lines were analyzed by numerical simulations based on the computational finite element method. The deformation of the electric-field lines between the nozzle and counter electrodes implies a lack of droplet adhesion onto the ternary ring electrode and a focus of electrospray. Finally, we demonstrated the ESD of polymer materials with an area of 371 ± 160 mm2 at a deposition rate of 314 ± 73 nm/min. The ESD technique is an important additive surface-modification method that is applicable to a variety of materials and suitable for highly viscous solutions and fragile biological samples.