Arrangement and method for controlling a micromechanical element
The invention concerns an arrangement for controlling a non-volatile memory arrangement for a circuit comprising: a micromechanical element coupled to a substrate; the micromechanical element being responsive to deflection means arranged on the substrate to control the movement of the micromechanical element between one or more stable states. In addition, the invention concerns a method for controlling a non-volatile memory device arrangement comprising: applying one or more signals to a deflection means for moving a micromechanical element between one or more stable states. To enhance the efficacy of the invention there is further provided a shorting circuit for use in the non-volatile memory arrangement.
1. A method for controlling a nonvolatile switch, comprising:
applying a first biasing voltage to a switching electrode;
moving a micromechanical element from a first state spaced from a contact electrode to a second state in contact with the contact electrode and spaced a first distance from the switching electrode; and
applying an electrical pulse to the switching electrode to move the micromechanical element to the first state, the electrical pulse falling at a rate that is faster than the mechanical resonance of the micromechanical element.
2. The method of claim 1 , wherein the first state is a stable state and the second state is a stable state.
3. The method of claim 2 , wherein applying the electrical pulse increases the elastic energy stored in the micromechanical element.
4. The method of claim 3 , wherein prior to applying the electrical pulse, the adhesive energy between the contact electrode and the micromechanical element is greater than the restoration force of the micromechanical element.
5. The method of claim 1 , wherein the micromechanical element has a first portion having a first bending stiffness and a second portion having a second bending stiffness that is greater than the first bending stiffness.
6. The method of claim 1 , further comprising charge transferring from the micromechanical element to the contact electrode to program the micromechanical element.
7. The method of claim 6 , further comprising deprogramming the micromechanical element.
8. The method of claim 7 , further comprising moving the micromechanical element to a location spaced a second distance from the switching electrode, wherein the micromechanical element remains in contact with the contact electrode while the micromechanical element moves to a location spaced a second distance from the switching electrode.
9. A method for controlling a nonvolatile micro-electromechanical system, comprising:
applying a first biasing voltage to a switching electrode;
moving a micromechanical element from a first state spaced from a contact electrode to a second state in contact with the contact electrode such that adhesive energy at the interface between the micromechanical element and the contact electrode is generated;
increasing the elastic energy of the micromechanical element to a value greater than the adhesive energy at the interface between the micromechanical element and the contact electrode; and
moving the micromechanical element to the first state.
10. The method of claim 9 , wherein the micromechanical element is coated with polymer.
11. The method of claim 10 , wherein the contact electrode is coated with polymer.
12. The method of claim 9 , further comprising charge transferring from the micromechanical element to the contact electrode to program the micromechanical element.
13. The method of claim 9 , wherein the micromechanical element remains spaced from the switching electrode when the elastic energy of the micromechanical element increases.
14. The method of claim 9 , further comprising removing the first biasing voltage before increasing the elastic energy of the micromechanical element.
15. The method of claim 9 , applying a voltage to the micromechanical element while the micromechanical element moves to the first state.
16. The method of claim 9 , wherein the micromechanical element remains in contact with the contact electrode while increasing the elastic energy of the micromechanical element.
17. A method for controlling a bi-stable micro-electromechanical system, comprising:
applying a first electrical signal to a switching electrode to move a micromechanical element from a first stable state spaced from a contact electrode to a second stable state in contact with the contact electrode;
removing the first electrical signal applied to the switching electrode;
applying a second electrical signal to the switching electrode to move the micromechanical element from the second stable state, wherein the second electrical signal is an electrical pulse that falls at a rate that is faster than the mechanical resonance of the micromechanical element; and then
moving the micromechanical element to the first stable state.
18. The method of claim 17 , wherein applying the second electrical signal increases the elastic energy stored in the micromechanical element.
19. The method of claim 17 , wherein the micromechanical element remains in contact with the contact electrode when the micromechanical element is moved from the second stable state.
20. The method of claim 17 , wherein applying the second electrical signal increases the elastic energy stored in the micromechanical element to a value that is greater than the adhesive forces present at the interface between the micromechanical element and the contact electrode.