Technical Approach - Release Mechanism

The scratch drive devices must remain attached to their underlying substrate throughout the fabrication process. However, they must be detached from the substrate prior to operation. So, a release mechanism is required. We would like this release mechanism to be compatible with batch fabrication. i.e. the devices should be able to self-release.

To accomplish this, the scratch drives are originally suspended above the substrate by a long thin beam. The beam is intentionally flawed where it joins the scratch drive plate. When voltage is first applied to the electrodes beneath the scratch drive, the electrostatic attraction draws the device towards the substrate. The resulting deformation stress in the beam is concentrated at the intentional flaw. The beam then snaps at the flaw and the device is released.