Aspects of fabrication and characterization of electro-thermal micro-actuators

• Autor(a) principal: Godoy,Paulo Henrique de
• Data de Publicação: 2007
• Outros Autores: Silva,Emílio Carlos Nelli
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Society of Mechanical Sciences and Engineering (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1678-58782007000100005
• topic: MEMS; micro-actuators; force measurement; displacement measurement; FE simulation

This study examines the behavior of well known simple thermal micro-actuators. This work describes some unexplored aspects of the employed methodology to produce these electro-thermal micro-actuators (ETMs). These information could be time saving for new groups to start research and development on electro-thermal actuators. The focus of the applied methodology is the use of the finite element method (FEM) applied to an iterative procedure to predict the behavior of the micro-actuators before production. The computational model is adjusted based on measurements of force and displacement. To be correctly applied, this methodology requires a sensitivity study of the material properties. The results emphasize the need to use FEM with more accurate thermal and mechanical properties, and to consider also the variation of these properties with temperature. We must also consider a careful definition of thermal boundary conditions and the effects of heat convection and radiation, due to deviations between experimental results and FE results. In this investigation, the structural material applied was Nickel, plated at about 1 µm/min. The experimental characterization was carried out in a micro probe station with a CCD (charge-coupled device) camera attached to it, and used a controlled voltage source.