Abstract: A gas storage apparatus includes a foam body having a negative Poisson's ratio, and a gas impregnated in closed cells of the foam body, the gas having a pressure above atmospheric pressure. A method of making a gas storage apparatus includes providing a first body comprising a precursor material, and, while the first body is in an atmosphere including a gas, applying a stimulus to the precursor material, the stimulus causing the precursor material to form a closed-cell porous foam structure having a negative Poisson's ratio. Cells of the closed-cell porous foam structure encapsulate the gas at a pressure above atmospheric pressure.

Abstract: A brick includes outer walls defining a hollow interior space, the outer walls including: substantially flat top and bottom walls; and side walls angled inwards toward a central portion of the NPR brick, such that application of a compressive force between the top and bottom walls causes a lateral dimension of the brick between opposite side walls to decrease. At least some of the outer walls of the brick include a material having a negative Poisson's ratio (NPR).

Abstract: Some tissue adhesives include a solid having bio-absorbable fibers and at least one of nano-spheres, micro-spheres, nano-tubules, or micro-tubules. A first layer of the solid has a positive Poisson's ratio and a second layer of the solid has a negative Poisson's ratio. In some cases, the second layer has been transformed from a positive Poisson's ratio material to a negative Poisson's ratio material. In some cases, an entire face of the first layer is in contact with an entire face of the second layer. In some cases, the second layer includes one or more pores, at least a portion of the one or more pores containing a secretion from one or more barnacles. In some cases, the secretion is configured to adhere the tissue adhesive to one or more layers of tissue to at least partially close a wound.

Abstract: A ski includes an elongated ski body having a bottom layer defining a bottom surface of the ski, a top layer defining a top surface of the ski, and a middle layer disposed between the bottom layer and the top layer, in which the middle layer includes a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1.

Abstract: The disclosure describes a zipper including two rows of zipper teeth, in which at least some of the zipper teeth include a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1, and a slider movably attached to one of the rows of the zipper teeth and configured to connect the two rows of zipper teeth when the slider is moved in a first direction and to disconnect the two rows of zipper teeth when the slider is moved in an opposite direction.

Abstract: An intraocular lens includes a substantially circular lens element formed of a transparent material and one or more haptics extending outwardly from an outer edge of the lens element. The one or more haptics are formed of a polymer foam material having a negative Poisson's ratio (NPR) and are configured to couple the intraocular lens to an eye of a patient. The lens includes an inner region having a first index of refraction and an outer region disposed circumferentially surrounding the inner region, the outer region having a second index of refraction different from the first index of refraction.

Abstract: An artificial heart valve includes a frame, one or more struts attached to the frame, and a leaflet configured to open and close a fluid flow path through the frame by moving in response to heartbeats. Movement of the leaflet is restricted by the one or more struts. The leaflet includes an inner leaflet body having a negative Poisson's ratio, and an outer leaflet body at least partially surrounding the inner leaflet body, the outer leaflet body having a positive Poisson's ratio.

Abstract: A racquet includes a handle; and a frame connected to an end of the handle, the frame defining a rounded interior space, the frame including a negative Poisson's ratio (NPR) foam material, in which the NPR foam material, and in which the frame has a Poisson's ratio of between 0 and ?1; and a network of strings stretched across the rounded interior space defined by the frame. A golf tee includes an elongated stem; and a head disposed at an end of the elongated stem and shaped to receive a golf ball; in which at least a portion of the golf tee is formed of a negative Poisson's ratio (NPR) foam material, in which the portion of the golf tee has a Poisson's ratio of between 0 and ?1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.

Abstract: A bone cement includes a liquid component including a monomer configured to polymerize upon curing of the bone cement; and a solid component dispersed in the liquid component, the solid component including a powder of a polymer; an initiator; and a powder of a piezoelectric ceramic. A cell culture dish includes a base; and walls connected to the base to define an interior of the cell culture dish, wherein at least a portion of an interior surface of the base includes a piezoelectric material.

Abstract: A propeller includes a rotatable hub and at least two propeller blades coupled to the rotatable hub. Each of the propeller blades is formed from a combination of a first material having a negative Poisson's ratio (NPR) and a second material having a positive Poisson's ratio (PPR). The first material and the second material can be layered or can be formed as a matrix with one of the first or second material embedded in the other. In a layered configuration, a layer of the first material is positioned between adjacent layers of the second material, and the layers can be connected by tabs of NPR material. The combination of the NPR and PPR materials improve the strength and impact resilience of the propeller blades compared to conventional materials.

Abstract: A stent for insertion into a vessel of a patient includes an inner tube comprising a positive Poisson's ratio (PPR) material and defining a lumen extending along a longitudinal axis of the stent; and an outer tube comprising a negative Poisson's ratio (NPR) foam material and disposed around an entirety of the inner tube, the outer tube extending along the longitudinal axis of the stent. The stent is configured to exhibit an auxetic behavior in response to a deformation of the stent. An outer surface of the second portion is configured to apply a pressure to an inner surface of the vessel when the stent is implanted into the vessel and the deformation is removed.

Abstract: A medical device includes a multi-layer body defining an interior space configured to contain a liquid. The multi-layer body includes a solid outer wall having a positive Poisson's ratio and a porous inner wall having a negative Poisson's ratio. A method of making a multi-layer body includes applying a stimulus to a precursor material to cause the precursor material to form a porous wall having a negative Poisson's ratio, and attaching a solid wall to the porous wall to form the multi-layer body, the solid wall having a positive Poisson's ratio. A suture includes one or more filaments, at least a first filament of the one or more filaments including a negative Poisson's ratio material. A medical device includes a biocompatible hydrogel, and the biocompatible hydrogel includes a composite of a first material having a negative Poisson's ratio and a second material having a positive Poisson's ratio.

Abstract: A medical implant includes a first implant body and a pre-coating covering at least a portion of an outer surface of the first implant body. The pre-coating has a negative Poisson's ratio. A method of making a medical implant includes applying a precursor material on a surface of a first implant body, the first implant body having a positive Poisson's ratio.

Abstract: A biocompatible seed for implantation in tissue of a patient includes an elongated body sized and shaped to be at least partially inserted into the tissue of the patient, in which the body includes a negative Poisson's ratio (NPR) material having a Poisson's ratio of between 0 and ?1. The seed can be a thermal seed configured to generate heat responsive to exposure to a magnetic field. The seed can be a seed for brachytherapy that includes an inner layer including a radioactive material and an outer layer including the NPR material.

Abstract: An ear plug includes an elongated body sized and shaped to be partially inserted into an ear canal of a wearer, in which the body includes a negative Poisson's ratio (NPR) polymer foam material having a Poisson's ratio of between 0 and ?1. A mouth guard includes an arc-shaped element sized to be received into a mouth of a wearer. The arc-shaped element has an outer wall, an inner wall, and a biting wall connecting the outer wall and the inner wall. The outer wall, the inner wall, and the biting wall define a channel that is sized to receive upper teeth of the wearer or lower teeth of the wearer. The outer wall, the biting wall, or both includes a negative Poisson's ratio (NPR) material having a Poisson's ratio between 0 and ?1.

Abstract: In an aspect, a sports ball includes a core including a negative Poisson's ratio (NPR) foam material, in which the core has a Poisson's ratio of between 0 and ?1, and in which the NPR foam material includes an NPR polymer foam; and a cover layer surrounding the core. In an aspect, a golf club includes an elongated shaft; a grip disposed at a first end of the elongated shaft; and a head connected to a second end of the elongated shaft, the head having a flat face configured for contact with a golf ball, in which the flat face is formed of a negative Poisson's ratio (NPR) foam material, in which the head has a Poisson's ratio of between 0 and ?1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.