Design and Comprehensive Study of a New Soft Electromagnetic Actuator: Mathematical Modeling, Numerical Analysis, and Experimental Evaluation

Soft robotics offers a flexible alternative to rigid systems, enabling safe and adaptive interaction in biomedical, wearable, and unstructured environments. Among available actuation methods, soft electromagnetic actuators are notable for their fast response, low operating voltage, and ease of integration. However, some designs require pre-stretching mechanism, which produces an external force to maintain the separation between the coil and permanent magnets. Additionally, there is a mechanical complexity and difficulty in calibrating the spring parameters precisely. Furthermore, the pre-stretching mechanism increases the electromagnetic force required to counteract the opposing spring force, leading to a significant increase in power consumption. Therefore, this paper presents MagFlex V-2, a soft actuator featuring an air gap between a coil and permanent magnets, encapsulated in silicone to eliminate the need for pre-stretching. Three evaluation approaches were employed: (1) experimental testing across 0–45 V, (2) finite element simulation in COMSOL, and (3) analytical modeling using energy-based methods and a magnetic dipole field. MagFlex V-2 exhibited voltage-induced contraction, reducing its length from 17.1 cm to 15.1 cm at 42.5 V. The displacement followed a nonlinear voltage relationship, becoming more linear with increased silicone stiffness. In addition, electromagnetic force showed high sensitivity to voltage and air gap, peaking at 7.03 N (analytical) and 7.43 N (numerical) at 0.5mmand 45 V. Furthermore, statistical analysis (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> > 0.05) confirmed that silicone damping and elasticity were not significant. Finally, electrical behavior showed close agreement among analytical, numerical, and experimental results at low currents, with deviations at higher voltages attributed to thermal effects.