Development of magnetoactive elastomers for sealing eye retina detachments

Magnetoactive elastomers (MAEs) on the basis of a silicone matrix filled with carbonyl iron microparticles are developed for an envisaged application in eye surgery for treatment of complicated retinal detachments. The proposed magnetic fixator of an eye retina consists of an MAE seal placed inside an eye in the area of a retinal break, and an external silicone sponge with embedded permanent magnets which can be sutured to the sclera to provide magnetic field acting on the internal MAE seal. For MAE seal development, MAEs of various compositions (containing 52-76 mass% of ferromagnetic iron microparticles) are synthesized and their surface, magnetic, mechanical, and rheological properties are investigated in external magnetic fields. To demonstrate MAEs efficacy as an element of the retina magnetic fixator, magnetic forces acting between MAE samples and systems of permanent magnets were measured in the curved configuration corresponding to the human eye geometry. It has been demonstrated that the pressure produced within the fixator can be varied in a wide range by tuning the MAE composition and MAE seal dimensions as well as by optimizing the size and configuration of permanent magnets within the external silicone sponge. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47425.