A novel electromagnetic microactuator with a stainless steel mas-spring structure

Abstract

Abstract Microactuators are one of the main components of the microelectromechanical and microfluidic systems and play a key role in their development. Many such systems, e.g. micropumps and microvalves, utilize an electromagnetic microactuator with a displacement range of a few micrometers traversed within a few seconds. Most of the electromagnetic microactuators have low lifetime and fracture toughness or low recovery speed. Microactuators with metallic mass-spring structure can overcome the mentioned disadvantages or limitations. This paper presents the design and fabrication of a novel stainless steel electromagnetic microactuator fabricated using micro-wire electrical discharge machining. The microactuator in question consists of a mass-and-spring structure made of 304 stainless steel, a permanent magnet made of NdFeB, and a microcoil. The impacts of the number of turns, distance, and electric current on the magnetic field of the microcoil and the displacement of the microactuator membrane with time have been investigated to determine the microactuator characteristics. The results indicated a displacement of about ±10 (20) μm within 7 s for an electric current of 1100 mA. This microactuator exhibits a faster response compared to the similar microactuators. Consequently, it can be used at higher operating frequencies and, thus, improves the fluid flow in micropumps.