Electrothermally excited plasma droplet evolution on the laser-patterned surface

Abstract

Droplet behavior involving electrothermal coupling fields has gradually attracted the attention of researchers, one of which includes electrosurgical scalpels that often contact biofluids. However, the evolution of bio-droplets exposed to the surface of electrosurgical scalpels is not yet well understood. Here, we experimentally studied the effect of different heating temperatures on plasma droplets on the laser-patterned surface (LPS) and the original surface (OS) under defined direct-current (DC) or alternating-current (AC) electric fields. The results show that at a lower heating temperature, the evolution of plasma droplets was dominated by electrolysis. Oxygen bubbles generated on the papillae on the LPS in the DC field inhibited the targeted adsorption of plasma proteins on this surface. In contrast, in the AC field, only a small number of bubbles was generated, which is not sufficient to inhibit protein adsorption, leading to the formation of coagulation on the papillae after heating. At higher heating temperatures, the rapid formation of coagulation resulted in the suppression of electrolysis. The plasma proteins were then transported by the Marangoni flow causing coagulation to reach a thickness of stress mutation. Stress release over the entire coagulation caused its edges to bend and then detach from the papillae. Thus, the LPS exhibited excellent anti-adhesive properties to plasma droplets under electrothermal excitations compared to the OS. This study provides valuable information for understanding the mechanisms of contact behavior between biofluids and electrosurgical scalpels and demonstrates great promise for their anti-adhesive performance.