ИСТИНА

Magnetoactive elastomers (MAE) are active polymer composites that consist of soft polymeric matrix and nano- to micro-sized ferromagnetic filler particles. They belong to the “smart” materials category and thus are highly responsive to the external magnetic field. As a result of filler particles restructuring MAEs exhibit a vast array of interesting physical effects: magnetostriction, magnetorheological effect, magnetically enhanced Payne effect, magnetic and mechanical hysteresis, memory effects etc. It follows from the above mentioned facts that MAE would be useful in any situation that requires external control over elastic subsystem in a device. This work’s main aim is to create and analyze the model of interaction between a MAE sample and a system of permanent magnets in order to utilize MAE as a magnetically controlled retinal seal in eye surgery. To perform computations we use commercially available software COMSOL Multiphysics that solves partial differential equations using finite-element method. The first point of interest considered was the influence of different geometric configurations on the interaction parameters. The second point included influence of magnetic configuration of the system (for example, magnetization orientation). The MAE samples were represented by cuboids or spherical segments to study the interaction for different form-factors of the system. Magnetic properties modeling included two main difficulties: non-uniform magnetization due to demagnetization field influence and the dependence of the magnetic permeability of the sample on external field. Using experimental data to check for inconsistencies various interaction parameters were obtained. The main result is the dependence of the force and pressure acting on the sample on the distance from the magnetic subsystem as well as many other geometric and magnetic parameters. The problem of the sample’s displacement allowed by the geometric constraints was considered in terms of tangent gradients and forces. System configurations optimal for eye surgery were proposed.