Stiction mitigation with integrated mech micro-cantilevers through vertical stress gradient control

Abstract

The present disclosure relates to the mitigation of stiction in MEMS devices. In some embodiments, a MEMS device may be provided with one or more restoration features that provide an assisting mechanical force for mitigating stiction. The restoration feature may be implemented as one or more deflectable elements, where the deflectable elements may have various configurations or shapes, such as a chevron, cross, and the like. For example, the restoration feature can be a cantilever that deflects when at least one component comes into contact or proximity with another component. Multiple restoration features also may be employed and placed strategically within the MEMS device to maximize their effectiveness in mitigating stiction.

1 . An electromechanical device comprising:
 a first component;   a second component movable relative to the first component in a first direction; and   at least one restoration feature, on the first component, that applies a restoring force to the second component in a second direction opposite to the first direction and comprises at least one deflecting portion that surrounds an opening in the first component and extends towards the second component when the first component and the second components are apart from each other.   
     
     
         2 . The electromechanical device of  claim 1 , wherein the at least one deflecting portion comprises a cantilever. 
     
     
         3 . The electromechanical device of  claim 1 , wherein the at least one deflecting portion comprises a plurality of leaves. 
     
     
         4 . The electromechanical device of  claim 1 , wherein the opening in the first component comprises a generally chevron-like shape. 
     
     
         5 . The electromechanical device of  claim 1 , wherein the opening in the first component comprises a generally cross-like shape. 
     
     
         6 . The electromechanical device of  claim 1 , wherein the at least one deflecting portion comprises a generally rectangular shape. 
     
     
         7 . The electromechanical device of  claim 1 , wherein the at least one restoration feature is positioned on a peripheral portion of the first component. 
     
     
         8 . The electromechanical device of  claim 1 , further comprising at least one restoration feature, on the second component, that applies a second restoring force to the second component in the second direction. 
     
     
         9 . The electromechanical device of  claim 1 , wherein the micro-electromechanical (MEMS) device is an interferometric modulator. 
     
     
         10 . The electromechanical device of  claim 9 , wherein the first component comprises a partially reflective layer and the second component comprises a reflective layer. 
     
     
         11 . The electromechanical device of  claim 10 , wherein the reflective layer is deformable to move in the first direction. 
     
     
         12 . The electromechanical device of  claim 10 , wherein the second component further comprises a deformable layer coupled to the reflective layer, the deformable layer configured to move in the first direction. 
     
     
         13 . The electromechanical device of  claim 1 , wherein the opening comprises an etch hole through the first component. 
     
     
         14 . The electromechanical device of  claim 1 , further comprising:
 a display;   a processor that is configured to communicate with the display, the processor being configured to process image data; and   a memory device that is configured to communicate with the processor.   
     
     
         15 . The electromechanical device of  claim 14 , further comprising a driver circuit configured to send at least one signal to the display. 
     
     
         16 . The electromechanical device of  claim 15 , further comprising a controller configured to send at least a portion of the image data to the driver circuit. 
     
     
         17 . The electromechanical device of  claim 14 , further comprising an image source module configured to send the image data to the processor. 
     
     
         18 . The electromechanical device of  claim 17 , wherein the image source module comprises at least one of a receiver, transceiver, and transmitter. 
     
     
         19 . The electromechanical device of  claim 14 , further comprising an input device configured to receive input data and to communicate the input data to the processor. 
     
     
         20 . An electromechanical apparatus comprising:
 means for partially reflecting light;   means for reflecting light, wherein the reflecting means is movable in a first direction relative to the partially reflecting means; and   means for applying a restoring force to the reflecting means, the restoring means on the partially reflecting means, the restoring force in a second direction opposite to the first direction, the restoring means surrounding an opening in the partially reflecting means and extending towards the reflecting means when the partially reflecting means and the reflecting means are apart from each other.   
     
     
         21 . The electromechanical apparatus of  claim 20 , wherein the reflecting means comprises a reflective layer disposed on a substrate. 
     
     
         22 . The electromechanical apparatus of  claim 20 , wherein the restoring means comprises a cantilever that curls towards the reflecting means. 
     
     
         23 . The electromechanical apparatus of  claim 20 , wherein the restoring means comprises a plurality of cantilevers that curl towards the reflecting means. 
     
     
         24 . The electromechanical apparatus of  claim 20 , wherein the restoring means minimizes stiction between the partially reflecting means and the reflecting means. 
     
     
         25 . An electromechanical device comprising:
 a first component;   a second component spaced from the first component and configured to move in a first direction between an undriven position and a driven position, the driven position located closer to the first component than the undriven position; and   at least one restoration feature, on the second component, that applies a restoring force to the second component in a second direction opposite to the first direction and comprises at least one deflecting portion that surrounds an opening in the second component and extends towards the first component when the second component is in the undriven position.