Elastic conductor
An elastic conductor includes a stretchable base, and conductors each having a longitudinal shape, being arranged on a surface of the stretchable base, and having a lower specific resistance and a higher modulus of elasticity than the stretchable base. In the first state, the conductors are spaced apart from each other in the second direction perpendicular or substantially perpendicular to the first direction, and are continuous in a section extending in the first direction as seen in the second direction from one end of the section to the other end of the section, in which a distance between the conductors adjacent to each other in the second direction in the second state is shorter than a distance between the conductors adjacent to each other in the second direction in the first state.
1. An elastic conductor comprising:
a stretchable base having conductivity; and
a plurality of conductors each having a longitudinal shape extending in a first direction and arranged on a surface of the stretchable base or inside the stretchable base, each of the plurality of conductors having a lower specific resistance and a higher modulus of elasticity than the stretchable base; wherein
the elastic conductor is changeable between a first state before a tensile force acts in the first direction and a second state in which the tensile force acts in the first direction to cause the elastic conductor to be expanded in the first direction;
in the first state, the plurality of conductors are spaced apart from each other in a second direction perpendicular or substantially perpendicular to the first direction, and are continuous in at least a partial section extending in the first direction as seen in the second direction from one end of the partial section to another end of the partial section in the first direction; and
a distance between conductors of the plurality of conductors adjacent to each other in the second direction in the second state is shorter than a distance between the conductors adjacent to each other in the second direction in the first state.
2. The elastic conductor according to claim 1 , wherein each of the plurality of conductors is made of a metal material in a bulk state or a metal foil.
3. The elastic conductor according to claim 1 , further comprising:
a restraint member having a higher modulus of elasticity than the stretchable base, the restraint member being structured to reduce or prevent expansion and contraction of the stretchable base in the second direction; wherein
in the at least a partial section, two or more conductors of the plurality of conductors are arranged side by side in the second direction, to define:
a dense region in which the plurality of conductors along a width of the stretchable base in the second direction are dense in number; and
a sparse region in which the plurality of conductors along the width of the stretchable base in the second direction are less dense in number than in the dense region; and
the restraint member is provided on a back surface of the stretchable base so as to overlap with the sparse region as seen in a direction perpendicular or substantially perpendicular to the surface of the stretchable base.
4. The elastic conductor according to claim 1 , further comprising:
a restraint member having a higher modulus of elasticity than the stretchable base, the restraint member being structured to reduce or prevent expansion and contraction of the stretchable base in the second direction; wherein
an electronic component mounted region including an electronic component mounted thereon is provided on the surface of the stretchable base, the surface being adjacent to the at least a partial section; and
the restraint member is provided on a back surface of the stretchable base or inside the stretchable base so as to overlap with the electronic component mounted region as seen in a direction perpendicular or substantially perpendicular to the surface of the stretchable base.
5. The elastic conductor according to claim 1 , further comprising:
an elastic base including a first main surface and a second main surface that face in opposite directions, the elastic base being structured to support the stretchable base and the plurality of conductors; wherein
the plurality of conductors are provided on the first main surface; and
the stretchable base is provided on the first main surface to cover the plurality of conductors.
6. The elastic conductor according to claim 5 , further comprising:
a restraint member having a higher modulus of elasticity than the elastic base, the restraint member being structured to reduce or prevent expansion and contraction of the elastic base in the second direction; wherein
in the at least a partial section, two or more conductors of the plurality of conductors are arranged side by side in the second direction, to define:
a dense region in which the plurality of conductors along a width of the stretchable base in the second direction are dense in number; and
a sparse region in which the plurality of conductors along the width of the stretchable base in the second direction are less dense in number than in the dense region; and
the restraint member is provided on the second main surface so as to overlap with the sparse region as seen in a direction perpendicular or substantially perpendicular to the second main surface.
7. The elastic conductor according to claim 5 , further comprising:
a restraint member having a higher modulus of elasticity than the elastic base, the restraint member being structured to reduce or prevent expansion of the elastic base in the second direction; wherein
an electronic component mounted region including an electronic component mounted thereon is provided on the surface of the stretchable base, the surface being adjacent to the at least a partial section; and
the restraint member is provided so as to overlap with the electronic component mounted region as seen in a direction perpendicular or substantially perpendicular to the second main surface.
8. The elastic conductor according to claim 1 , wherein the stretchable base has a rectangular or substantially rectangular shape.
9. The elastic conductor according to claim 1 , wherein the stretchable base is made of a material including a rubber material or a resin kneaded with conductive powder.
10. The elastic conductor according to claim 1 , wherein the conductive powder is a metal selected from the group consisting of Ag, Cu, Al, Zn, Ni, and Sn, or an alloy including two or more of the metals.
11. The elastic conductor according to claim 1 , wherein the stretchable base is made of a material including a thermoplastic elastomer kneaded with carbon filler.
12. The elastic conductor according to claim 1 , wherein each of the plurality of conductors is made of a copper foil.
13. The elastic conductor according to claim 1 , wherein the plurality of conductors are arranged in a staggered manner.
14. The elastic conductor according to claim 1 , wherein some conductors of the plurality of conductors are linearly arranged so as to be spaced apart from each other in the first direction.
15. The elastic conductor according to claim 1 , wherein the plurality of conductors are arranged in a plurality of lines sequentially arranged so as to be spaced apart from each other in second direction.
16. The elastic conductor according to claim 15 , wherein the plurality of lines consists of five lines.
17. The elastic conductor according to claim 15 , wherein the plurality of lines consists of three lines.
18. The elastic conductor according to claim 1 , wherein
one end of a conductor of the plurality of the conductors in the first direction is connected to an electrode portion provided on a first end side of stretchable base in the first direction; and
one end of another conductor of the plurality of the conductors in the first direction is connected to another electrode portion provided on a second end side of stretchable base in the first direction opposite to the first end side.
19. The elastic conductor according to claim 18 , wherein each of the electrode portion and the another electrode portion has a rectangular or substantially rectangular shape with a short side direction corresponding to the first direction and a long side direction corresponding to the second direction.