Hydrophobic PTFE coatings on endoscopic lenses by RF magnetron sputtering

Minimally invasive procedures such as laparoscopy and endoscopy require clear visualization, often hindered by fluid adhesion and condensation on endoscope lenses. This study explores the application of polytetrafluoroethylene (PTFE) as a hydrophobic coating on styrene–acrylonitrile (SAN) and acrylonitrile–butadiene–styrene (ABS) substrates using radio-frequency (RF) magnetron sputtering for 30, 60, 90, and 120 min. Coated surfaces were evaluated for water contact angle and optical transmittance. Fourier-transform infrared spectroscopy confirmed successful PTFE deposition, while scanning electron and atomic force microscopy revealed that SAN developed a rougher surface than ABS, resulting in a higher water contact angle. RF-sputtered PTFE coatings significantly improved both hydrophobicity and light transmittance. Notably, 60 min of RF sputtering on ABS produced superior transmittance and acceptable hydrophobicity compared with uncoated, dip-coated, and spin-coated controls. Similarly, RF-coated SAN showed enhanced performance over its uncoated and coated counterparts. Compared with commercially coated silicon dioxide and titanium dioxide samples, RF-coated SAN and ABS demonstrated superior hydrophobicity and transmittance. While their contact angles were lower than those of untreated and coated polycarbonate, their optical clarity was significantly better. These results highlight the potential of RF magnetron sputtering to develop durable, transparent, anti-fogging coatings, offering a promising solution for improving medical optical device performance.