US 11,722,074 B2
Vibration-driven energy harvesting element
Hiroshi Toshiyoshi, Tokyo (JP); Hiroaki Honma, Tokyo (JP); and Hiroyuki Mitsuya, Sayama (JP)
Assigned to The University of Tokyo, Tokyo (JP); and Saginomiya Seisakusho, Inc., Tokyo (JP)
Appl. No. 17/289,115
Filed by The University of Tokyo, Tokyo (JP); and Saginomiya Seisakusho, Inc., Tokyo (JP)
PCT Filed Nov. 15, 2019, PCT No. PCT/JP2019/044860
§ 371(c)(1), (2) Date Apr. 27, 2021,
PCT Pub. No. WO2020/101014, PCT Pub. Date May 22, 2020.
Claims priority of application No. 2018-215630 (JP), filed on Nov. 16, 2018.
Prior Publication US 2022/0014118 A1, Jan. 13, 2022
Int. Cl. H02N 1/08 (2006.01)
CPC H02N 1/08 (2013.01) 3 Claims
OG exemplary drawing
 
1. A vibration-driven energy harvesting element, comprising:
a pair of fixed electrode portions; and
a movable electrode portion that is arranged between the pair of fixed electrode portions and has a pair of a plurality of movable comb teeth extending from opposite sides of the movable electrode portion,
wherein:
each of the pair of fixed electrode portions has a plurality of fixed comb teeth facing a respective one of the opposite sides of the movable electrode portion,
the plurality of moveable comb teeth on the opposite sides of the movable electrode portion being inserted between the plurality of fixed comb teeth of the respective fixed electrode portions,
the vibration-driven energy harvesting element has a three-terminal structure in which the fixed comb teeth and/or the movable comb teeth are electretized,
the movable electrode portion is configured to move laterally in a plane containing the fixed comb teeth such that an overlap of the plurality of movable comb teeth with the plurality of fixed comb teeth in the plane alternately increases and decreases when the movable comb teeth move laterally between the pair of fixed electrodes,
a gap dimension of a clearance region between the fixed comb teeth and the movable comb teeth is smaller than 20 μm,
an aspect ratio, which is a ratio of a dimension of the clearance region in a comb tooth height direction between the fixed comb teeth and the movable comb teeth to the gap dimension of the clearance region between the fixed comb teeth and the movable comb teeth, is 20 or more,
in the fixed comb teeth that face each other, vertical surfaces of the fixed comb teeth are straight in the comb tooth height direction from a top to a bottom of the fixed comb teeth, and
the dimension of the clearance region in the comb tooth height direction is larger than 100 μm.