Design, Manufacture and Validation of Linear Electromagnetic Actuator with Force Range of Milli Newton

In recent years, linear electromagnetic actuators have gained special attention in small robot actuation and calibration of milli newton thruster stands. In this paper, a linear electromagnetic actuator with a force range of milli newtons is designed and manufactured. In this regard, first the analytical relationships of the magnetic field and Lorentz force were derived and then, based on the desired design criteria meaning high force sensitivity, low heat loss and minimum geometric dimensions and weight, the appropriate design parameters of the electromagnetic actuator is obtained. According to the results, the  obtained force constant is approximately 1 mN/A while the maximum power loss is 1 mW at available stroke of 10 mm. Finally, a prototype of the linear electromagnetic actuator is manufactured and experiments are performed to validate the electromagnetic actuator. For this purpose, a precision scale with an accuracy of 0.01 gr and a power supply with a resolution of 1 mA is utilized. The results showed that the maximum difference between the calculated and measured force was 2.5%. Therefore, there is a good correlation between the experimental data and the corresponding analytical values.