Elastomeric micro electro mechanical systems

• US 5,642,015 A
• Filed: 05/01/1995
• Issued: 06/24/1997
• Est. Priority Date: 07/14/1993
• Status: Expired due to Fees

• Current Assignee: University of British Columbia
• Original Assignee: University of British Columbia
• Inventors: Bolleman, Brent J., Whitehead, Lorne A.
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US08/431,735
• Time in Patent Office: 785 Days
• Field of Search: 310/309, 310/328, 310/311
• US Class Current: 310/309
• CPC Class Codes: B06B 1/0292 Electrostatic transducers, e.g. electret-type
• CPC Class Codes: G01H 11/06 by electric means
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence

Abstract

An electromechanical transducer having a substrate bearing a plurality of elastomeric microstructures with a microelectrode on each microstructure. A power supply is connected to the microelectrodes for controlled application to them of an electrical potential which alternately induces forces of attraction between adjacent pairs of microelectrodes, causing controlled, time-varying displacement of the microelectrodes. Alternatively, a further plurality of microelectrodes (or one or more macroelectrodes) are elastomerically supported above the microelectrodes, with the power supply being connected to the macroelectrode(s) such that the electrical potential applied between the microelectrodes and macroelectrode(s) alternately induces forces of attraction between the microelectrodes and macroelectrode(s), causing controlled, time-varying displacement of the microelectrodes relative to the macroelectrode(s). The macroelectrode(s) can also be applied to a side of the substrate opposite the microstructures.

Claims

1. An electromechanical transducer, comprising:

(a) a first substrate bearing a first plurality of elastomeric microstructures on one side of said substrate;

(b) a first microelectrode on each one of said first plurality of microstructures; and

,

(c) power supply means electrically connected to said microelectrodes for controlled application of an electrical potential to said microelectrodes.

2. An electromechanical transducer as defined in claim 1, wherein said electrical potential alternately induces forces of attraction between adjacent pairs of said microelectrodes, causing controlled, time-varying displacement of said microelectrodes.

3. An electromechanical transducer as defined in claim 1, further comprising one or more macroelectrodes on an opposed side of said substrate, wherein:

(a) said power supply means is further electrically connected to said one or more macroelectrodes; and

,

(b) said electrical potential alternately induces forces of attraction between said microelectrodes and said one or more macroelectrodes, causing controlled, time-varying displacement of said microelectrodes relative to said one or more macroelectrodes.

4. An electromechanical transducer as defined in claim 1, further comprising one or more macroelectrodes elastomerically supported above said microelectrodes, wherein:

(a) said power supply means is further electrically connected to said one or more macroelectrodes; and

,

(b) said electrical potential alternately induces forces of attraction between said microelectrodes and said one or more macroelectrodes, causing controlled, time-varying displacement of said microelectrodes relative to said one or more macroelectrodes.

5. An electromechanical transducer as defined in claim 1, wherein said first plurality exceeds 1,000.

6. An electromechanical transducer as defined in claim 1, wherein:

(a) said first substrate is an elastomeric sheet material; and

,

(b) said microstructures are formed as integral surface features of said sheet material.

7. An electromechanical transducer as defined in claim 1, further comprising:

(a) a second substrate bearing a second plurality of elastomeric microstructures, said second substrate adjacent to and facing said first substrate, with said second plurality of elastomeric microstructures contacting said first substrate; and

,

(b) a second plurality of microelectrodes on said second substrate;

wherein said power supply means is further electrically connected to said second microelectrodes for controlled application of said electrical potential to said second microelectrodes to alternately induce forces of attraction between said first and second pluralities of microelectrodes, causing controlled, time-varying displacement of said first and second pluralities of microelectrodes.

8. An electromechanical transducer as defined in claim 1, further comprising:

(a) a second substrate bearing a second plurality of elastomeric microstructures, said second substrate adjacent to and facing said first substrate, with said second plurality of elastomeric microstructures contacting said first substrate; and

,

(b) one or more macroelectrodes supported above said microelectrodes by said second plurality of elastomeric microstructures;

wherein said power supply means is further electrically connected to said one or more macroelectrodes for controlled application of said electrical potential to said one or more macroelectrodes to alternately induce forces of attraction between said microelectrodes and said one or more macroelectrodes, causing controlled, time-varying displacement of said microelectrodes relative to said one or more macroelectrodes.

9. An electromechanical transducer as defined in claim 1, wherein:

(a) adjacent pairs of said first microelectrodes are separated by a gas-filled gap, said gas characterized by a Paschen minimum distance "d" at a particular gas pressure; and

,

(b) said gap width is less than twice said Paschen minimum distance "d".

10. An electromechanical transducer as defined in claim 1, wherein said first microelectrodes comprise an electrically conductive elastomer.

11. An electromechanical transducer as defined in claim 1, wherein said microstructures are geometrically configured for directional deposition of electrically conductive material on said microstructures to form said microelectrodes as a predetermined micro-pattern of surface deposits on said microstructures.

12. An electromechanical transducer as defined in claim 1, further comprising a recess between each adjacent pair of said first plurality of said microstructures, each of said recesses defining a surface path length between said first microelectrodes on said adjacent microstructures, said surface path length substantially exceeding any direct path distance between said first microelectrodes on said adjacent microstructures.

13. An electromechanical transducer as defined in claim 7, further comprising a plurality of gas flow reservoirs in said second substrate for gas flow from between said microelectrodes into and out of said reservoirs during said displacement of said microelectrodes.

14. An electromechanical transducer as defined in claim 4, further comprising a plurality of gas flow reservoirs in said first substrate for gas flow from between said microelectrodes into and out of said reservoirs during said displacement of said microelectrodes.

15. An electromechanical transducer as defined in claim 1, wherein said microelectrodes have individual cross-sectional area less than 0.01 mm².

16. An electromechanical transducer as defined in claim 2, wherein said microelectrodes have individual cross-sectional area less than 0.01 mm² and said displacement exceeds one percent of the square root of said cross-sectional area.

17. An electromechanical transducer as defined in claim 1, further comprising:

(a) a second plurality of elastomeric microstructures on an opposed side of said substrate; and

,

(b) a second microelectrode on each one of said second plurality of microstructures;

wherein said power supply means is further electrically connected to said second microelectrodes for controlled application of an electrical potential to said second microelectrodes.