Design and fabrication of novel micro electromagnetic actuator

Arabian Journal for Science and Engineering, 2018

Lab-on-chip devices essentially require micropumps and valves which incorporate a microactuating mechanism to control fluid flow. In this work, a non-spiral type planar microcoil is reported for implementing an electromagnetic microactuator. The effect of variation in coil geometries on the microactuator performance is analyzed for the first time. The microcoil fabricated and characterized in this work considerably reduces the number of lithography layers, thus improving the ease of fabrication while reducing the series coil resistance. The microcoil structures are further analyzed for the microactuator performance using finite element method, and the effect of coil geometries on the electromagnetic force generated by the actuator is studied. Microfabrication and electrical characterization results of the non-spiral planar microcoils show the influence of the same on the actuator performance. A tapered square microcoil geometry is proposed to improve the outputs from the actuator. Keywords Lab-on chip • Finite element method • Microactuator • Non-spiral planar microcoils • Tapered square geometry

This paper reports a compact design of electromagnetically driven MEMS micro-actuator utilizing planar electromagnetic coil on PCB (Printed Circuit Board). The micro-actuator device consists of an NdFeB permanent magnet, thin silicon membrane and planar micro-coil which fabricated using simple standard MEMS techniques with additional bonding step. Two planar coils designs including planar parallel and spiral coil structure with various coil geometry are chosen for the study. Analysis of the device involves the investigation of electromagnetic and mechanical properties using finite element analysis (FEA), the measurement of the membrane deflection and functionality test. The measurement results show that the thin silicon membrane is able to deform as much as 12.87 µm using planar spiral micro-coil. Reasonable match between simulation and measurement of about 82.5% has been revealed. The dynamic response test on actuator driven by parallel planar coil shows that silicon membrane effectively deformed in 40 s for an input electrical power of only 150 mW. It is also concluded that planar parallel coil is considered for the simple structure and easy fabrication of the actuator system. This study will provide important parameters for the development of compact and simple electromagnetic micro-actuator system for fluidic injection system in lab-on-chip.

ARPN journal of engineering and applied sciences, 2015

An electromagnetic MEMS actuator with planar electromagnetic micro-coil on a PCB (Printed Circuit Board) is reported. The microactuator device consists of permanent magnet made of NdFeB, silicon based membrane and planar micro-coil electroplated on PCB. Each part of the system was fabricated using simple MEMS technique and bonded together using epoxy material. The performance of the fabricated device was tested by measuring the deflection capability of the silicon membrane. The measurement results showed that a planar spiral micro-coil is able to generate magnetic flux density and to deform a 20 μm thin silicon membrane with a maximum deflection height of 12.87 μm. The functionality of the actuator system was tested by measuring the dynamic response in a period of 50 seconds. Test on planar parallel round micro-coil resulted in a maximum membrane displacement in 40 s for all tested input power from 100 to 1000 mWatt. The results from this study will benefit the future development of...

Polymers

In this study, we present a comprehensive review of polymer-based microelectromechanical systems (MEMS) electromagnetic (EM) actuators and their implementation in the biomedical engineering field. The purpose of this review is to provide a comprehensive summary on the latest development of electromagnetically driven microactuators for biomedical application that is focused on the movable structure development made of polymers. The discussion does not only focus on the polymeric material part itself, but also covers the basic mechanism of the mechanical actuation, the state of the art of the membrane development and its application. In this review, a clear description about the scheme used to drive the micro-actuators, the concept of mechanical deformation of the movable magnetic membrane and its interaction with actuator system are described in detail. Some comparisons are made to scrutinize the advantages and disadvantages of electromagnetic MEMS actuator performance. The previous ...

Design, Characterization, and Packaging for MEMS and Microelectronics, 1999

In this paper, a parametrical method is developed to design a magnetic microactuator. The method is based on modeling the magnetic microactuator using the finite element analysis software that can be used to calculate the energy density and magnetic force. Here, the concept of design on experiments (DOE) is used to identify critical parameters that affect the performances of the electromagnetic microactuator. Numerical simulation results from a series of DOE have indicated that the dimension of core and the magnetic material block have the influence on planar electromagnetic actuators. When the length of the magnetic components is equal to that of outer diameter of coil circuit, we obtain the best efficiency in magnetic force. Furthermore, when we increase the thickness of the magnetic materials block or shorten the distance between the coils and magnetic material block, the magnetic force will increase dramatically. In addition, we can achieve a great magnetic force when the combination ratio of the length of the core is half of the magnetic material block. Simulation results have shown that electromagnetic actuators with high aspect ratio planar coil could sustain higher electrical current that consequently increases the magnetic force. During the realistic fabrication, the thick resist patterning and electroplating technologies is used to fabricate the above-mentioned electromagnetic microactuator. Experimental results indicated that the magnetic force follows closely to the simulation results.

Sensors and Actuators A: Physical, 2000

This paper describes the operation of a magnetic microactuator. A prototype device consisting of a Nd-Fe-B permanent magnet, a silicon membrane and an electroplated copper coil is used to verify models and to predict the deflection of the magnetic microactuator. The analysis of this device involves the investigation of its electromagnetic and mechanical behaviour using analytical methods and finite Ž. element analysis FEA. A design procedure for a magnetic microactuator is also outlined. The prototype device was characterised and the measured results compared to the theoretical data. Results show that the deflection of the device may be predicted to an accuracy of 20%.

International Journal of Mechanical Engineering and Robotics Research

An electromagnetic (EM) micro-actuator with silicon membrane has been fabricated and characterized. The studied silicon based membrane is used as an actuator of a micropump system driven by magnetic force. The actuator consists of two main parts, namely, the electromagnetic part that generates electromagnetic field and the magneto mechanical part that enables the membrane deformation depending on the magnetic force strength on the silicon membrane. A standard Micro Electronic Mechanical System (MEMS) process was implemented to fabricate the actuator with an additional bonding between the actuator membrane and electromagnetic coil. The measurement results show that the 20 μm thin silicone membrane is capable of deformation with a maximum membrane deflection of approximately 4.5 μm which will be useful for a reliable fluids pump in a continuous drug delivery system. 

Middle-East Journal of Scientific Research

In this work, the design and optimization of electromagnetic micro-actuator induced by an embedded planar micro-coil is discussed. The actuator design is optimized to enable significant increase of the actuation force and magnetic flux density at low power consumption. Therefore, this work is focused on theoretical analysis of magnetically actuated membrane which has been induced by a planar embedded micro-coil. The design and geometry of the planar micro-coil are discussed in detail in this report. Furthermore, the parameters of coil dimension such as width, space and number of turn, were varied and compared by implementing 3 different permanent magnet materials (Neodymium, SmCo and AlNiCo) to obtain optimum force. As the results, the geometry of the micro-coil and the permanent magnet material greatly affect to the magnetic flux density and are highly related to the generated force. This work is greatly benefit for microfluidic injection system integrated in Lab-on-Chip.

RSM2013 Proc. 2013, Langkawi, Malaysia

In this work, a theoretical analysis on the magnetic force generation of micro-actuator driven by planar microcoil is reported. The actuator design is optimized to increase the magnetic force and flux density that is useful for mechanical membrane deformation of an actuator. Therefore, this work is focused on the design and simulation of actuator material and structure using a finite element analysis method. As the results, the obtained magnetic force of maximum 11.4 mN has been observed for the actuator design having coil geometry of width w = 100 μm, space s =100 μm, turn N = 20 and thickness t =20 μm with NdFeB as magnet material. Hence, the optimized design geometry of the coil can be used as reference for the fabrication of electromagnetic actuator for micropump application.

Microsystem Technologies, 2014