Electronically latching micro-magnetic switches and method of operating same

• US 6,633,212 B1
• Filed: 03/06/2001
• Issued: 10/14/2003
• Est. Priority Date: 09/23/1999
• Status: Expired due to Term

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Shen, Jun, Ruan, Meichun, Wheeler, Charles
• Primary Examiner(s): Donovan, Lincoln
• Application Number:
  US09/799,831
• Time in Patent Office: 952 Days
• Field of Search: 335/78-86, 335/124, 335/128, 257/414, 257/421, 257/531, 200/180-181, 369/112, 359/290
• US Class Current: 335/78
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: H01H 2050/007 Relays of the polarised type, e.g. the MEMS relay beam having a preferential magnetisation direction
• CPC Class Codes: H01H 50/005 using micromechanics
• CPC Class Codes: H01H 67/22 Switches without multi-position wipers

Abstract

A switch with an open state and a closed state suitably includes a cantilever having first and second state corresponding to the open and closed states of the switch, respectively. The switch may also include a magnet configured to provide an electromagnetic field that maintains said cantilever in one of the first and second states. Various embodiments may also include an electrode or electrical conductor configured to provide an electric potential or electromagnetic pulse, as appropriate, to switch the cantilever between the first and second states. Various embodiments may be formulated with micromachining technologies, and may be formed on a substrate.

Claims

1. A magnetically sensitive actuator comprising:

a magnet proximate to a substrate, wherein said magnet produces a first magnetic field;

a cantilever having a magnetic material and a longitudinal axis, said magnetic material making said cantilever sensitive to said first magnetic field that is approximately perpendicular to said longitudinal axis, wherein said cantilever is operable to rotate between a first and second state based on said first magnetic field producing a torque in said magnetic material of said cantilever that maintains said cantilever in one of said first and second states;

a conductor configured to conduct a current, wherein said current induces a torque in said cantilever based on a second magnetic field, wherein a component of said second magnetic field parallel to said longitudinal axis adjusts said direction of said torque produced by said first magnetic field in said magnetic material of said cantilever such that said conductor switches said cantilever between said first and second states; and

a hinge positioned between said magnet and said cantilever that couples said cantilever to said substrate.

2. The actuator of claim 1 wherein said cantilever is approximately parallel to said substrate in said first state.

3. The actuator of claim 1 wherein said cantilever is approximately perpendicular to said substrate in said second state.

4. The actuator of claim 1 wherein said cantilever is coupled to a mirror.

5. The actuator of claim 1 wherein said conductor is coupled to said substrate.

6. The actuator of claim 1 wherein said conductor is coupled to said cantilever.

7. The actuator of claim 1 further comprising a stopper, wherein said stopper is configured to receive said cantilever in one of said first and second states.