Micro Cinema

Joint work: Karl Bohringer, Bruce Darling, Noel MacDonald.

Thanks to Martin Berggren, Bruce Land, and Chris Pelkie, Scientific Visualization, Cornell Theory Center.

Actuator Array (MPEG computer animation):
A to-scale CAD model of single crystal silicon micro actuators. The actuators are shown in yellow, the aluminum electrodes are white. If we apply an AC voltage between the silicon subtrate and the electrodes, we generate electrostatic forces that induce oscillation. The actuators are asymmetric: there are tips on just one side of the suspended actuator grid. One die contains more than 100 actuators. Dies can be "tiled" together to continuously fill the wafer with thousands of actuators.
Actuator Array (MPEG computer animation):
Zoom into an array of micro actuators. The actuators are drawn in yellow, eletrodes for electrostatic actuation are white, and the wafer substrate is shown in blue. These devices are fabricated in single crystal silicon technology with the SCREAM process. A single actuator is approximately 400 um long. All features in this model are to scale.

Equilibrium Condition (MPEG computer animation):
A polygonal object moves in a two-dimensional force field that pushes with constant magnitude towards a straight center line (drawn in magenta). We see the centroids (in green) of the object sections left and right of the center line. The resulting forces for the left and right sections are also shown (in pink). The object comes to rest when the left and right forces are of equal magnitude, and the connection between the centroids (in black) is perpendicular to the center line. (The center of mass of the object is drawn in red.)
One-Step Alignment Strategy (MPEG computer animation):
The object is moving in the force field until it reaches a stable equilibrium positions. We can predict this position from the force field and the object geometry, and we can show that for any given polygonal part, there is only a small finite number of such positions. The force field can be generated for example by an array of micro actuators, or by a vibrating plate.
Two-Step Alignment Strategy (MPEG computer animation):
With two sensorless alignment steps the object can be oriented uniquely (up to symmetry). A geometric analysis of the object shows that it has two stable equilibrium positions. From this analysis we can generate the appropriate two-step alignment strategy.