Selectively Tuning a Buckled Si/SiO2 Membrane MEMS through Joule Heating Actuation and Mechanical Restriction

摘要

This research followed previous work and attempted to modify the spring in two ways. First, a Ti/Au meander resistor was deposited atop the membrane in an effort to actuate the membrane and change the spring constant. Secondly, a series of overhanging cantilevers were attached to the bulk substrate surrounding the membrane in an effort to constrain the membrane buckling deflection to the negative stiffness region. Membrane buckling was investigated through Finite Element analysis (FEA) and analytical equations. Deflections were measured using an interferometric microscope (IFM) and force/deflection measurements were captured using a unique measurement scheme. The results concluded that by introducing a thermal stress, the membrane could be actuated with a corresponding 3x increase in spring constant. Additionally, the overhanging beams restricted the membrane deflection by up to 30%, but, because of a lack in beam stiffness, failed to restrict the membrane to the negative stiffness region. This research laid the ground work for future work in this area.