Bio-inspired electrosurgical knife with lubricant-assisted porous-groove surface and micro-serrated edge for reducing tissue adhesion and thermal injury.

Tissue adhesion and thermal injury remain major challenges in high-frequency electrosurgery because carbonized residues can accumulate on the electrode surface and reduce cutting stability. To address this issue, a coating-free bio-inspired electrosurgical knife was designed and fabricated from 316L stainless steel by selective laser melting. Inspired by loach-skin lubrication and anti-fouling characteristics, a porous-groove blade surface was designed for lubricant storage and transport. Inspired by crab-chela serrations, a micro-serrated cutting edge was introduced to reduce cutting resistance. Fluid-flow simulation showed that the porous-groove surface promoted lubricant retention and local recirculation, reducing near-wall resistance by up to 20.73%. Friction tests indicated that D_p = 350 μm and L_p = 800 μm produced the lowest lubricated friction coefficient of 0.362 among the tested porous-groove surfaces. Static cutting simulation and cutting-force tests confirmed that the micro-serrated edge reduced cutting resistance, with the lowest peak cutting force of approximately 0.605 N obtained at H₁ = 300 μm. Powered electrosurgical tests showed that the sample with D_p = 350 μm, L_p = 800 μm, and H₁ = 300 μm achieved the lowest apparent adhesion mass of 2.07 ± 0.67 mg, corresponding to a 61.5% reduction compared with the DT401 commercial smooth control electrode. The thermal damage areas on the upper and lateral tissue surfaces were reduced by 56.75% and 54.44%, respectively. These results demonstrate an effective engineering strategy for improving the anti-adhesion and thermal-safety performance of electrosurgical knives.