Fabrication and characterization of micro electromagnetic linear actuators

Abstract

This paper on the reports design, fabrication and position monitoring of a micro electromagnetic linear actuator. The actuator consists of stator, slider, guide, sensors and affiliated jigs. Actuation is achieved through ampere force between two phase micro-coils (copper) on the stator and permanent magnets (thick NdFeB film) on the slider. During the slider’s movement in the guide slot, tunnelling magneto-resistance (TMR) sensors are utilized to sense the magnetic field to realize position monitoring. TMR is chosen because it owns advantages of small size, large sensitivity and easy integration with micro devices. Purpose of this research is to report the micro fabrication of thick magnet films and testify the possibility of using TMR as position monitoring sensors. Actuators are fabricated by micro-electro-mechanical system process (stator and guide) and precise machining (slider and jigs). Surface magnetic field generated by the slider, driving characteristics of the actuator as well as the position monitoring capabilities of TMR elements are simulated and experimented, respectively. The slider attains 60 mm s−1 speed by sinusoidal input signal at 300 Hz frequency and 0.2 A current magnitude. Actuation bandwidth is between 300 Hz and 500 Hz at open loop condition. The maximum position monitoring error in present work is 2.2% with 101 μm value for 4.5 mm stroke.

Simultaneous enhancement of coercivity and saturation magnetization in high-performance anisotropic NdFeB thick films with a Dy diffusion layer

“…[1][2][3] With the development of integration technology and film technology, NdFeB thick films have potential applications in magnetic sensors and microelectromechanical systems (MEMS). [4][5][6][7][8] However, for NdFeB thick films, the key magnetic properties such as coercivity, remanent magnetization, and perpendicular magnetic anisotropy (PMA) decrease gradually with the growth of thickness after the thickness reaches a certain level. 9 It is important to improve the magnetic properties of NdFeB thick films.…”

Research on the Design and Control of Advanced Experimental Setups Used in Actuators and Platforms Characterization

“…• Characterization of custom designed positioning subassemblies The proper design and functioning of this type of actuators depend on reliable measurements taken with high precision equipment and powerful software. A review of the literature underlines the need of actuators characterization, to optimize the designing, manufacturing, and validation process [8], [9], [10].…”

A long-stroke planar linear actuator equipped with magnetic guide

“…For a electromagnetic actuator with long stroke up to several millimeters, the mover as the moving part of the actuator is susceptible to external interference including impact and vibration during the movement. As one of the solutions, mechanical rail has been demonstrated in the previous research to guide the mover along the moving direction [13][14][15]. However, the mechanical rail complicates the manufacturing and assembling process of the actuator.…”