Micro-electro-thermo-magnetic Actuators for MEMS Applications
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Date
2008-04-08T14:38:43Z
Authors
Forouzanfar, Sepehr
Journal Title
Journal ISSN
Volume Title
Publisher
University of Waterloo
Abstract
This research focuses on developing new techniques and designs for highly con-
trollable microactuating systems with large force-stroke outputs. A fixed-fixed mi-
crobeam is the actuating element in the introduced techniques. Either buckling
of a microbridge by thermal stress, lateral deflection of a microbridge by electro-
magnetic force, or combined effects of both can be employed for microactuation.
The proposed method here is MicroElectroThermoMagnetic Actuation (METMA),
which uses the combined techniques of electrical or electro-thermal driving of a mi-
crobridge in the presence of a magnetic field. The electrically controllable magnetic
field actuates and controls the electrically or electrothermally driven microstruc-
tures. METMA provides control with two electrical inputs, the currents driving
the microbridge and the current driving the external magnetic field. This method
enables a more controllable actuating system. Different designs of microactuators
have been implemented by using MEMS Pro as the design software and MUMPs as
the standard MEMS fabrication technology. In these designs, a variety of out-of-
plane buckling or displacement of fixed-fixed microbeams have been developed and
employed as the actuating elements. This paper also introduces a novel actuating
technique for larger displacements that uses a two-layer buckling microbridge actu-
ated by METMA. Heat transfer principles are applied to investigate temperature
distribution in a microbeam, electrothermal heating, and the resulting thermoelas-
tic effects. Furthermore, a method for driving microactuators by applying powerful
electrical pulses is proposed. The integrated electromagnetic and electrothermal
microactuation technique is also studied. A clamped-clamped microbeam carry-
ing electrical current has been modeled and simulated in ANSYS. The simulations
include electrothermal, thermoelastic, electromagnetic, and electrothermomagnetic
effects. The contributions are highlighted, the results are discussed, the research
and design limitations are reported, and future works are proposed.
Description
Keywords
MEMS, Actuator, Buckling, Electromagnetic, Thermal, Thermomagnetic, Electrothermomagnetic, Micromotor, Microbridge, Fixed-Fixed beam