Abstract: Disclosed is a zero Poisson's ratio structure including a central pillar; at least two branched connectors extending radially from a lower end of the central pillar, wherein each of the branched connectors includes: a first segmental portion extending inclinedly upwardly or downwardly from the central pillar; and a second segmental portion extending inclinedly downwardly or upwardly from a distal point of the first segmental portion, wherein the extension directions of the first and second segmental portions are opposite to each other; and each leg extending perpendicularly downwardly from a distal point of each of the second segmental portions, wherein due to a force pressing the central pillar, each of an angle between the central pillar and the first segmental portion, an angle between the first segmental portion and the second segmental portion, and an angle between the second segmental portion and the leg is variable.

Abstract: Disclosed is a frequency-selective signal damper including: a viscous polymer exhibiting non-Newtonian fluid behavior; and hydrogel exhibiting sol-gel phase transition. The viscous polymer exhibits shear thinning in a damping region or a noise region, and the hydrogel has a sol phase in the damping region or the noise region. The viscous polymer is gelatin, and the hydrogel is chitosan.

Abstract: Disclosed are an anisotropic mechanical expansion (anisotropic Poisson's ratio) substrate and a crack-based pressure sensor using the same. The substrate having an anisotropic Poisson's ratio includes a first layer having linear concave and convex patterns arranged in parallel to each other on a surface thereof; and a second layer having linear convex and concave patterns respectively engaged with the linear concave and convex patterns of the first layer on a surface thereof, wherein the first layer and the second layer are stacked with each other so that the linear convex and concave patterns of the second layer are respectively engaged with the linear concave and convex patterns of the first layer, wherein an elastic modulus of the first layer is different from an elastic modulus of the second layer.

Abstract: Disclosed is a zero Poisson's ratio structure including a central pillar; at least two branched connectors extending radially from a lower end of the central pillar, wherein each of the branched connectors includes: a first segmental portion extending inclinedly upwardly or downwardly from the central pillar; and a second segmental portion extending inclinedly downwardly or upwardly from a distal point of the first segmental portion, wherein the extension directions of the first and second segmental portions are opposite to each other; and each leg extending perpendicularly downwardly from a distal point of each of the second segmental portions, wherein due to a force pressing the central pillar, each of an angle between the central pillar and the first segmental portion, an angle between the first segmental portion and the second segmental portion, and an angle between the second segmental portion and the leg is variable.

Abstract: Disclosed are an anisotropic mechanical expansion (anisotropic Poisson's ratio) substrate and a crack-based pressure sensor using the same. The substrate having an anisotropic Poisson's ratio includes a first layer having linear concave and convex patterns arranged in parallel to each other on a surface thereof; and a second layer having linear convex and concave patterns respectively engaged with the linear concave and convex patterns of the first layer on a surface thereof, wherein the first layer and the second layer are stacked with each other so that the linear convex and concave patterns of the second layer are respectively engaged with the linear concave and convex patterns of the first layer, wherein an elastic modulus of the first layer is different from an elastic modulus of the second layer.

Abstract: A crack sensor with crack healing is provided. The sensor having: a substrate; a conductive layer disposed on the substrate, wherein the conductive layer contains cracks formed therein; and a polymer layer disposed between the substrate and the conductive layer, or disposed on the conductive layer and not between the substrate and the conductive layer; wherein a restoring force of the polymer layer suppresses further growth of the cracks or restores cracks.

Abstract: A crack sensor with crack healing is provided. The sensor having: a substrate; a conductive layer disposed on the substrate, wherein the conductive layer contains cracks formed therein; and a polymer layer disposed between the substrate and the conductive layer, or disposed on the conductive layer and not between the substrate and the conductive layer; wherein a restoring force of the polymer layer suppresses further growth of the cracks or restores cracks.

Abstract: A device for stimulating a body using light is disclosed. The device for stimulating a body using light includes a transmission light generator capable of generating light; and a body organ stimulator that generates stimulating light for stimulating a body organ when transmission light received from the transmission light generator includes light of a preset wavelength band.