Evaluation of actuation compatibility and homogeneities for MRI-powered ferromagnetic sphere

Figures & data

Figure 1. Force model.

Figure 2. (a) Schematic of magnetic field environment and (b) mesh grid of the region.

Table 1. Parameters of FEM model and ferromagnetic sphere.

Coils	Radius (mm)	Diameter of copper wire (mm)	Coil turns
x Axis Helmholtz coil	300	1.0	100
y Axis Helmholtz coil	700	1.0	100
x Axis Maxwell coil	300	0.8	200
y Axis Maxwell coil	700	0.8	200

Figure 3. Current-dependent magnetic torque (a) and magnetic force (b) of ferromagnetic sphere at indicated radii.

Figure 4. Radii dependence of magnetic torque (a) and magnetic force (b) of ferromagnetic sphere (I_y = 7 A).

Figure 5. Comprehensive influence of radius and I_y currents on magnetic torque (a) and magnetic force (b) with ferromagnetic sphere at I_x = 7 A.

Table 2. Significance analysis for ferromagnetic at given conditions.

	R	I	RI	R^2	I^2	R^2I	RI^2	R^3	I^3
F	<0.0001	0.0892	<0.0001	<0.0001	0.6813	0.0655	0.9035	0.2424	0.5976
	R^2 = 0.9506
T	<0.0001	<0.0001	<0.0001	<0.0001	0.1580	0.0001	0.9154	0.9384	0.2288
	R^2 = 0.9577

Figure 6. Average field intensity (a), (c) and FHEs (b), (d) in the ROI at different distances.

Figure 7. Calculated contents obtained using Equation (4) (a) and Equation (5) (b) against the measured ones.