Abstract: A self-healing composite system includes a solid polymeric matrix and a woven structure in the matrix. The woven structure includes a plurality of fibers, and a first plurality of microfluidic channels. The microfluidic channels include a first healing agent in the channels. The woven structure also may include a second plurality of microfluidic channels that include a second healing agent in the channels.

Abstract: A microvascular system includes a solid polymeric matrix and a woven structure in the matrix. The woven structure includes a plurality of fibers, and a plurality of microfluidic channels, where at least a portion of the microfluidic channels are interconnected. The microvascular system may be made by forming a composite that includes a solid polymeric matrix and a plurality of sacrificial fibers in the matrix, heating the composite to a temperature of from 100 to 250° C., maintaining the composite at a temperature of from 100 to 250° C. for a time sufficient to form degradants from the sacrificial fibers, and removing the degradants from the composite. The sacrificial fibers may include a polymeric fiber matrix including a poly(hydroxyalkanoate) and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the fiber matrix, where the concentration of the metal in the fiber matrix is at least 0.1 wt %.

Abstract: A composite material includes a solid polymer matrix, a plurality of capsules and a liquid, in the capsules. The liquid includes from 50 to 100 wt % of a solvent, and from 0 to 50 wt % of a polymerizer. There is no polymerizer outside of the capsules. The solid polymer matrix may include a native activating moiety for the polymerizer. The solvent may have a swelling ratio with the solid polymer matrix of at least 1.1 and/or may have a polarity ET of from 0.10 to 0.50.

Abstract: A method of making a sacrificial fiber, comprising: forming a molten sacrificial composition comprising a poly(hydroxyalkanoate) and a metal catalyst; extruding the molten sacrificial composition to form a sacrificial fiber comprising the poly(hydroxyalkanoate) and the metal catalyst, where the concentration of the metal catalyst in the sacrificial fiber is at least 0.1 wt %.

Abstract: A thermally degradable polymeric sheet, comprising: a poly(hydroxyalkanoate); and a metal selected from the group consisting of an alkali earth metal and a transition metal; where the volume fraction of the metal in the sheet is at least 0.1 vol %.

Abstract: A method of making capsules includes forming a mixture including a core liquid, a polyurethane precursor system, a first component of a two-component poly(urea-formaldehyde) precursor system, and a solvent. The method further includes emulsifying the mixture, adding a second component of the two-component poly(urea-formaldehyde) precursor system to the emulsified mixture, and maintaining the emulsified mixture at a temperature and for a time sufficient to form a plurality of capsules that encapsulate at least a portion of the core liquid. The capsules made by the method may include a polymerizer in the capsules, where the capsules have an inner capsule wall including a polyurethane, and an outer capsule wall including a poly(urea-formaldehyde). The capsules may include in the solid polymer matrix of a composite material.

Abstract: A method of making a composite material provides a composite material that includes a polymeric layer and a substrate, in contact with the polymeric layer, where the substrate includes a substrate matrix, a first microfluidic network in the substrate matrix and in fluid communication with the polymeric layer, and a polymerizer in the first microfluidic network. The method includes forming the first microfluidic network in the substrate matrix, where the first microfluidic network is in fluid communication with a surface of the substrate matrix. The method further includes contacting the surface of the substrate matrix with the polymeric layer, and placing the polymerizer in the first microfluidic network.

Abstract: A self-indicating material system may include a solid polymer matrix having a first color, a first plurality of capsules in the matrix, and a plurality of particles in the matrix. The first plurality of capsules includes a first reactant, and the plurality of particles includes a second reactant, which forms a product when in contact with the first reactant. When a crack forms in the polymer matrix, at least a portion of the first plurality of capsules is ruptured, the first and second reactants form the product in the matrix, and the portion of the polymer matrix containing the product has a second color different from the first color. A self-indicating material system may include a solid polymer matrix, a plurality of capsules in the matrix, and an activator in the matrix, where the polymer matrix includes a first polymer and has a first color, the plurality of capsules includes a polymerizer, and the activator is an activator for the polymerizer.

Abstract: A partially degradable polymeric fiber includes a thermally degradable polymeric core and a coating surrounding at least a portion of the core. The thermally degradable polymeric core includes a polymeric matrix including a poly(hydroxy-alkanoate), and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the core polymeric matrix. The concentration of the metal in the polymeric matrix is at least 0.1 wt %. The partially degradable polymeric fiber may be used to form a microvascular system containing one or more microfluidic channels.

Abstract: A reinforced composite material includes a solid polymer matrix, a reinforcing material in the solid polymer matrix, and a first plurality of capsules. The reinforcing material includes a surface. The capsules are on the surface of the reinforcing material, and include a liquid healing agent. The amount of the healing agent of the capsules is at least 0.01 milligrams per square centimeter of the surface area of the reinforcing material.

Abstract: An autonomic conductivity restoration system includes a solid conductor and a plurality of particles. The particles include a conductive fluid, a plurality of conductive microparticles, and/or a conductive material forming agent. The solid conductor has a first end, a second end, and a first conductivity between the first and second ends. When a crack forms between the first and second ends of the conductor, the contents of at least a portion of the particles are released into the crack. The cracked conductor and the released contents of the particles form a restored conductor having a second conductivity, which may be at least 90% of the first conductivity.

Abstract: A self-healing composite system includes a solid polymeric matrix and a woven structure in the matrix. The woven structure includes a plurality of fibers, and a first plurality of microfluidic channels. The microfluidic channels include a first healing agent in the channels. The woven structure also may include a second plurality of microfluidic channels that include a second healing agent in the channels.

Abstract: An autonomous battery shutdown system includes a battery including an anode and a cathode, and an electrolyte composition between the anode and the cathode. The electrolyte composition includes an ionically conductive liquid containing lithium ions, and temperature-sensitive particles including a polymer having a melting temperature between 60° C. and 120° C. When the temperature of the battery exceeds 120° C., the temperature-sensitive particles form an ion barrier that traverses the battery. The resulting shutdown battery may have a specific charge capacity that is more than 98% lower than the specific charge capacity of the original battery.

Abstract: A method of making capsules includes forming a mixture including a core liquid, a polyurethane precursor system, a first component of a two-component poly(urea-formaldehyde) precursor system, and a solvent. The method further includes emulsifying the mixture, adding a second component of the two-component poly(urea-formaldehyde) precursor system to the emulsified mixture, and maintaining the emulsified mixture at a temperature and for a time sufficient to form a plurality of capsules that encapsulate at least a portion of the core liquid. The capsules made by the method may include a polymerizer in the capsules, where the capsules have an inner capsule wall including a polyurethane, and an outer capsule wall including a poly(urea-formaldehyde). The capsules may include in the solid polymer matrix of a composite material.

Abstract: A microvascular system includes a solid polymeric matrix and a woven structure in the matrix. The woven structure includes a plurality of fibers, and a plurality of microfluidic channels, where at least a portion of the microfluidic channels are interconnected. The microvascular system may be made by forming a composite that includes a solid polymeric matrix and a plurality of sacrificial fibers in the matrix, heating the composite to a temperature of from 100 to 250° C., maintaining the composite at a temperature of from 100 to 250° C. for a time sufficient to form degradants from the sacrificial fibers, and removing the degradants from the composite. The sacrificial fibers may include a polymeric fiber matrix including a poly(hydroxyalkanoate) and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the fiber matrix, where the concentration of the metal in the fiber matrix is at least 0.1 wt %.

Abstract: A composite material precursor composition includes a matrix precursor, a first plurality of capsules including a liquid polymerizer, an activator, and an accelerant. The liquid polymerizer polymerizes when in contact with the activator, and the accelerant is an accelerant for the polymerization of the liquid polymerizer. The composite material precursor may be used to form a composite material that includes a solid polymer matrix, the first plurality of capsules in the solid polymer matrix, the activator in the solid polymer matrix, and the accelerant in the solid polymer matrix.

Abstract: A mechanochromic material includes a polymer having a backbone containing a mechanophore.

Abstract: A self-indicating material system may include a solid polymer matrix having a first color, a first plurality of capsules in the matrix, and a plurality of particles in the matrix. The first plurality of capsules includes a first reactant, and the plurality of particles includes a second reactant, which forms a product when in contact with the first reactant. When a crack forms in the polymer matrix, at least a portion of the first plurality of capsules is ruptured, the first and second reactants form the product in the matrix, and the portion of the polymer matrix containing the product has a second color different from the first color. A self-indicating material system may include a solid polymer matrix, a plurality of capsules in the matrix, and an activator in the matrix, where the polymer matrix includes a first polymer and has a first color, the plurality of capsules includes a polymerizer, and the activator is an activator for the polymerizer.

Abstract: An autonomic conductivity restoration system includes a solid conductor and a plurality of particles. The particles include a conductive fluid, a plurality of conductive microparticles, and/or a conductive material forming agent. The solid conductor has a first end, a second end, and a first conductivity between the first and second ends. When a crack forms between the first and second ends of the conductor, the contents of at least a portion of the particles are released into the crack. The cracked conductor and the released contents of the particles form a restored conductor having a second conductivity, which may be at least 90% of the first conductivity.

Abstract: A composite material includes a solid polymer matrix, a plurality of capsules and a liquid, in the capsules. The liquid includes from 50 to 100 wt % of a solvent, and from 0 to 50 wt % of a polymerizer. There is no polymerizer outside of the capsules. The solid polymer matrix may include a native activating moiety for the polymerizer. The solvent may have a swelling ratio with the solid polymer matrix of at least 1.1 and/or may have a polarity ET of from 0.10 to 0.50. A composite material includes a solid polymer matrix, a plurality of capsules and a liquid, in the capsules. The liquid includes from 50 to 100 wt % of a solvent, and from 0 to 50 wt % of a polymerizer. There is no polymerizer outside of the capsules. The solid polymer matrix may include a native activating moiety for the polymerizer. The solvent may have a swelling ratio with the solid polymer matrix of at least 1.1 and/or may have a polarity ET of from 0.10 to 0.50.