Systems and methods for micromechanical displacement-based logic circuits
The present disclosure relates to a micromechanical displacement logic, signal propagation system that makes use of first and second bistable elements, and first and second mounting structures arranged adjacent opposing surfaces of the first bistable element. A plurality of pivotal lever arms are used to support the first bistable element in either one of two positions of equilibrium. A support structure and a compressible flexure element disposed between the support structure and the first mounting structure apply a preload force to the first mounting structure, which imparts the preload force to the first bistable element. The first bistable element is moveable from one of the two stable equilibrium positions to the other in response to an initial signal applied thereto. The preload force, at least one stiffness characteristic of the lever arms, and a compressibility of a compressible coupling element which links the second bistable element to the first, are all selected to tune signal propagation from the first bistable element to the second bistable element.
1. A micromechanical displacement logic, signal propagation system, comprising:
a first bistable element;
a first mounting structure arranged adjacent a first surface of the first bistable element;
a second mounting structure arranged adjacent a second surface of the first bistable element, wherein the second surface opposes the first surface, and such that the first bistable element is disposed between the first and second mounting structures;
a support structure;
a compressible flexure element disposed between the support structure and the first mounting structure to apply a preload force to the first mounting structure;
a plurality of lever arms for supporting the first bistable element between the first and second mounting structures in either one of two stable equilibrium positions, and applying the preload force to the bistable element, the first bistable element being moveable from one of the two stable equilibrium positions to the other in response to an initial signal applied thereto;
an additional movably supported element; and
a compressible coupling linkage element coupled at a first side to the first bistable element and at a second side to the movable supported element; and
wherein a preload force applied to the plurality of lever arms, a stiffness characteristic of the lever arms, and a compressibility of the compressible coupling linkage element, control signal propagation from the first bistable element to the movable element.
2. The system of claim 1 , wherein the additional movably supported element comprises an additional bistable element supported for translating movement along an axis in common with the first bistable element.
3. The system of claim 2 , wherein the plurality of lever arms form first and second lever arms, and are generally incompressible and apply a compressive force to the bistable element depending in part on the preload force applied using the compressible flexure element, and such that the first bistable element assumes either one of the two laterally spaced apart equilibrium positions, and the first and second lever arms operate as translation bearings.
4. The system of claim 3 , wherein propagation of the initial signal is influenced by a length “L” of each of the lever arms.
5. The system of claim 4 , wherein propagation of the initial signal is influenced by a compression of the first bistable element divided by the length L of one of the lever arms, and wherein the lever arms are all of equal length.
6. The system of claim 5 , wherein propagation of the initial signal is influenced by an axial stiffness K t of the lever arms.
7. The system of claim 6 , wherein the axial stiffness K t comprises a non-dimensional stiffness, and wherein K t represents a traverse stiffness of the lever arms divided by the axial stiffness of the lever arms.
8. The system of claim 7 , wherein propagation of the initial signal is further controlled by a non-dimensional ratio K c , wherein K c is a coupling stiffness imparted by the coupling linkage linking the first and additional bistable elements, divided by the axial stiffness of the lever arms.
9. A micromechanical displacement logic, signal propagation system, the system comprising:
a first bistable element;
a first mounting structure arranged adjacent a first surface of the first bistable element;
a second mounting structure arranged adjacent a second surface of the first bistable element, wherein the second surface opposes the first surface, and such that the first bistable element is disposed between the first and second mounting structures;
a support structure;
a compressible flexure element disposed between the support structure and the first mounting structure to apply a preload force to the first mounting structure;
a first lever arm coupling the first surface of the first bistable element with the first mounting structure;
a second lever arm coupling the second surface of the first bistable element to the second mounting structure;
the first and second lever arms being generally incompressible and applying a compressive force to the first bistable element depending in part on the preload force applied using the compressible flexure element, and such that the first bistable element assumes either first or second laterally spaced apart equilibrium positions, and the first and second lever arms operate as translation bearings;
a second bistable element arranged laterally of the first bistable element;
a compressible coupling linkage coupling the second bistable element and the first bistable element; and
wherein a stiffness (K t ) experienced by the first bistable element is influenced by the lever arms, the coupling linkage, an angle of the first lever arm relative to a reference axis, and a characteristic of the compressible coupling linkage are cooperatively configured to enable the second bistable element to be moved along with the first bistable element when the first bistable element is caused to move, in response to an initial signal, from one of the first or second laterally spaced apart equilibrium positions to the other, such that the initial signal acting on the first bistable element is propagated to the second bistable element and causes movement of the second bistable element from a first position to a second position.
10. The system of claim 9 , wherein propagation of the initial signal is influenced by a length “L” of each of the lever arms.
11. The system of claim 10 , wherein propagation of the initial signal is influenced by a compression of the first bistable element divided by the length L of one of the lever arms, and wherein the lever arms are all of equal length.
12. The system of claim 11 , wherein propagation of the initial signal is influenced by an axial stiffness K t of the lever arms.
13. The system of claim 12 , wherein the axial stiffness K t comprises a non-dimensional stiffness, and wherein K t represents a traverse stiffness of the lever arms divided by the axial stiffness of the lever arms.
14. The system of claim 13 , wherein propagation of the initial signal is further controlled by a nondimensional ratio K c , wherein K c is a coupling stiffness imparted by the coupling linkage linking the first and second bistable elements, divided by the axial stiffness of the lever arms.
15. The system of claim 14 , wherein the first bistable element has the same potential energy when positioned in either the first or second laterally spaced apart equilibrium positions.
16. The system of claim 15 , wherein sensitivity to movement of the first bistable element between the first and second laterally spaced apart equilibrium positions is controlled in part by the preload force applied via the compressible flexure element;
wherein the preload force is designated by “Y”; and
wherein the preload force Y non-linearly influences a displacement of the first bistable element.
17. The system of claim 16 , wherein:
a value of the preload force comprises a value of at least 0.1; and
a value of K t is less than 2*Y.
18. The system of claim 17 , further comprising:
an additional support structure;
an additional compressible flexure element coupled to the additional support structure; and
third and fourth lever arms each coupled at one end to the bistable element and at an opposite ends to the first mounting structure and the second mounting structure.
19. A method for forming a micromechanical displacement logic circuit to propagate a signal, the method comprising:
supporting a first bistable element using a plurality of pivotal lever arms from a spaced apart pair of mounting structures;
applying a predetermined preload force to the first bistable element through the pivotal lever arms such that the first bistable element is displaceable between first and second spaced apart positions of equilibrium;
coupling a second bistable element to the first bistable element using a compressible coupling linkage element; and
using at least the predetermined preload force, a length of the lever arms, an axial stiffness of the lever arms, and a transverse stiffness of the lever arms, to control a sensitivity of the bistable element to movement in response to receiving an applied signal thereto, such that propagation of the applied signal to the second bistable element is controlled.