Manufacturing Process and Thermal Stability of Nanophotonic Soft Contact Lenses

Abstract

Hydrogels have peculiar physical and chemical properties and therefore, are used in a variety of biomedical applications including drug delivery agents, prosthetic devices, the repair and replacement of soft tissues, contact lenses, etc. Consequently, investigation of mechanical, physical and chemical properties is crucial in biomedical application of hydrogels. Poly (2-hydroxyethyl methacrylate) (pHEMA), as a biocompatible hydrogel, was first hydrogel used for making soft contact lenses. Many researches have been modified pHEMA with the aim of improving its properties. Application of nanotechnology is one of the possible solutions for improving the characteristics of this biocompatible hydrogel. In this paper, polyhydroxyethyl methacrylate was used as standard material for soft contact lenses (SL 38). This material was incorporated with fullerene C-60 (SL38-A), fullerol C-60(OH)(24) (SL 38-B) and fullerene metformin hydroxylate C-60(OH)(12)(OC4N5H10)(12) (SL 38-C), respectively. Three new nanophotonic soft contact lenses were made. The main goal of this research was to develop appropriate process parameters for soft contact lens micro-turning. Also, studying the thermal decomposition of standard soft contact lens, pHEMA, as well as three new nanophotonic soft contact lenses was one of the main objectives. Results have shown that manufacturing process of nanofotonic soft contact lens is considered to be a micro-turning process regarding the cutting depth and tool nose ratio. Thermal stability of all three nanofotonic soft contact lenses was significantly improved comparing to the standard soft contact lens. Still, further research needs to be done so these nonophotonic soft contact lenses could find practical application in the field of biomedical engineering.