This Java Applet simulates a MEMS switch using non-linear dynamic models adapted from "Numerical Simulations and Novel Constant-Charge Biasing Method for Capacitive RF MEMS Switch" by JB Lee and Charles L GoldSmith and "Nonlinear Electro-Mechanical Modeling of MEMS Switches" by Jeremy Muldavin and Gabrial Rebeiz.

1.0 Input Values

     Use the drop down boxes to select a value, or enter your own in the allowed space. Entered values should be in the same units as those found in the connecting drop down box and in scientific notation.

2.0 Output Equations

     If the output box reports an error, the values input do not allow for the differential equation to be solved with real roots, and different input is required. Try reducing the height of the MEMS bridge over the electrode, or altering the size of the bridge. If there is an error, the graphs and visual representation will not be accurate.

3.0 Visual Panel

     The visual representation will automatically update after each input change. By clicking on the buttons in the visual panel, the device can rotate to allow different views.

4.0 Graphs

     The two graphs show the height of the bridge over the electrode (y-axis) with respect to time as well as the speed (y-axis) with respect to time. These graphs are updated using the output panel’s equations. In the evaluation box beneath each graph, a time value can be input to produce an output of z(t) or dz(t)/dt; this value must be input in microseconds.

5.0 Animation

     Using the “Stop” (square button), “Play” (triangle), or “Pause” (two rectangles), the visual representation will show the bridge drop down to the electrode. The clock contained in the purple box indicates the amount of time that has passed. In addition, a vertical line on each graph indicates the corresponding time value on each curve. If the “Stop” button is selected, the animation returns to the initial state, whereas “Pause” causes the animation to freeze instantaneously.

     In addition, the speed of the animation can be selected by adjusting the speed slider. Using the time slider, the user can manually adjust the visual to a particular point in time (which is shown in the purple time box).


© The University of Texas at Dallas, 2005 Written by Katie Roberts-Hoffman and Justin Marcus