Nepenthes alata inspired anti-sticking surface via nanosecond laser fabrication

Severe tissue adhesion on the surface of electrosurgical electrodes due to instantaneous high temperature and insufficient lubrication-caused friction has been a great challenge in minimally invasive surgery. Inspired by the unidirectional spreading of liquid and the rapid self-replenishment of the liquid film on the peristome of Nepenthes alata, an anisotropic self-replenishing liquid-infused surface (ASR-LIS) is fabricated via nanosecond laser direct engraving followed by sputtering TiO2 coatings. This facile method attributes a programmable spot shaping process which create unique multilevel structure that endows an enhanced capillary forces and longterm lubricant storage during liquid transport on the ASR-LIS. The ASR-LIS surface with TiO2 coating exhibits more excellent silicone oil-philic and hydrophilic properties. By contrast to the initial electrode, the ASR-LIS electrode showed significantly reduced adhesion, cutting force, and tissue damage. Additionally, liquid on ASR-LIS can spread directionally against thermal gradient from cold region to hot region maintaining a stable lubrication state of the surface. Moreover, the ASR-LIS surface has antibacterial effect and biocompatibility against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This innovative ASR-LIS design offers insight into applying tissue antiadhesion to electrosurgical instruments.