Numerical Analysis of Thermally Induced Micro Fiber Deformation Using a High Frequency Magnetic Field in Human Lung

This paper presents a numerical model to externally induce deformation of a micro fiber introduced inside a human lung pathway. The fiber contains ferromagnetic nano particles and has a cross-section of 0.4 × 0.22 μm and length of 20 μm. The fiber heating is achieved by applying an external high frequency magnetic field (2.6 kA/m, 1.0 MHz) to induce eddy currents in the ferromagnetic materials. Prediction of the thermal bending of the fiber requires a complicated multi-physics numerical modeling process. This finite element model is constructed in this paper to calculate the electromagnetic energy dissipation within the fiber. The deposited energy is coupled to a heat-transfer model to calculate the temperature rise. The distribution of temperature inside the fiber then allows prediction of fiber deformation. A tip displacement is up to 2.2 μm is achieved in the structural phase of the analysis. This is the first attempt to use thermal heating induced by a high frequency oscillatory magnetic field to cause deformation of a foreign Nano Electro-Mechanical-System (NEMS) in the human lunge aerosol system.