Abstract: The present disclosure is drawn to 3-dimensional printed parts that can include a conductive composite portion and an insulating portion. The conductive composite portion can include a matrix of fused thermoplastic polymer particles interlocked with a matrix of sintered elemental transition metal particles. The insulating portion can include a matrix of fused thermoplastic polymer particles that are continuous with the matrix of fused thermoplastic polymer particles in the conductive composite portion. The insulating portion can be substantially free of sintered elemental transition metal particles and can include transition metal oxide bronze particles.

Abstract: A strain sensor can include a resistor, a first electrical contact at a first end of the resistor, and a second electrical contact at a second end of the resistor. The resistor can be formed of a matrix of sintered elemental transition metal particles interlocked with a matrix of fused thermoplastic polymer particles.

Abstract: A 3-dimensional printed part can include a part body including a first matrix of fusing agent and thermoplastic polymer powder, a security feature including a second matrix of fusing agent, thermoplastic polymer powder, and photoluminescent agent, and a masking feature including a third matrix of fusing agent and thermoplastic polymer powder. The security feature can be positioned beneath and visible through the masking feature upon photoluminescent emission of the security feature.

Abstract: In an example, an apparatus includes processing circuitry comprising a model assessment module to identify an indication of a conductive element within object model data representing an object to be printed and a print instruction module to generate print instructions to generate the object. The print instructions may include an instruction to print conductive agent to form the conductive element and an instruction to print a fusing agent comprising an instruction to reduce an amount of fusing agent to be printed in a region of the conductive element compared to at least one other region of the object.

Abstract: The present disclosure describes materials, methods, and systems for three-dimensional printing. In one example, a three-dimensional printing kit can include a fusing agent and a microbe-inhibiting agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation and convert the radiation energy to heat. The microbe-inhibiting agent can include a liquid vehicle and a metal bis(dithiolene) complex. The disclosure also describes methods of three-dimensional printing that utilize a metal-containing microbe-inhibiting material, which can be a metal bis(dithiolene) complex or other materials.

Abstract: In an example method for forming three-dimensional (3D) printed electronic parts, a build material is applied. An electronic agent is selectively applied in a plurality of passes on a portion of the build material. A fusing agent is also selectively applied on the portion of the build material. The build material is exposed to radiation in a plurality of heating events. During at least one of the plurality of heating events, the portion of the build material in contact with the fusing agent fuses to form a region of a layer. The region of the layer exhibits an electronic property. An order of the plurality of passes, the selective application of the fusing agent, and the plurality of heating events is controlled to control a mechanical property of the layer and the electronic property of the region.

Abstract: The present disclosure is drawn to 3D printing kits, multi-fluid kits for 3D printing, and methods of making 3D printed articles. In one example, a 3D printing kit can include a powder bed material, a fusible fluid, and a magnetic fluid. The powder bed material can include polymer particles. The fusible fluid can include water and a radiation absorber. The fusible fluid can be to selectively apply to the powder bed material. The magnetic fluid can include magnetic particles, and the magnetic fluid can be to selectively apply to the powder bed material.

Abstract: A method for forming parts with electrically conductive features includes applying a layer of thermoplastic polymer powder particles in a powder bed and selectively applying an aqueous pretreat composition including a metal chloride salt on a portion of the layer. A conductive fusing ink including transition metal particles and a dispersing agent is selectively applied onto the applied aqueous pretreat composition on the portion of the layer, wherein the dispersing agent binds to, and passivates surfaces of the transition metal particles. The layer is exposed to electromagnetic radiation to fuse the thermoplastic polymer powder particles in the portion of the layer and sinter the transition metal particles, thereby forming a conductive feature.

Abstract: In an example method for forming three-dimensional (3D) printed electronic parts, a build material is applied. An electronic agent is selectively applied in a plurality of passes on a portion of the build material. A fusing agent is also selectively applied on the portion of the build material. The build material is exposed to radiation in a plurality of heating events. During at least one of the plurality of heating events, the portion of the build material in contact with the fusing agent fuses to form a region of a layer. The region of the layer exhibits an electronic property. An order of the plurality of passes, the selective application of the fusing agent, and the plurality of heating events is controlled to control a mechanical property of the layer and the electronic property of the region.

Abstract: In an example, a composition for three-dimensional (3D) printing includes a polymer build material and a non-conductive fusing agent dispensable onto the polymer build material to form a polymer-fusing agent composite portion when heated to a sintering temperature, a conductive agent dispensable onto on the polymer build material to form a polymer-conductive agent composite portion when heated at least to the sintering temperature, the conductive agent comprising: at least one conductive particulate present in an amount of from about 10% to about 60% of a total weight of the conductive agent; at least one co-solvent present in an amount of from about 10% to about 50% of a total weight of the conductive agent; and an additive present in an amount of from about 0% to about 10% of a total weight of the conductive agent.

Abstract: The present disclosure is drawn to 3D printing kits, multi-fluid kits for 3D printing, and methods of making 3D printed articles. In one example, a 3D printing kit can include a powder bed material, a fusible fluid, and a magnetic fluid. The powder bed material can include polymer particles. The fusible fluid can include water and a radiation absorber. The fusible fluid can be to selectively apply to the powder bed material. The magnetic fluid can include magnetic particles, and the magnetic fluid can be to selectively apply to the powder bed material.

Abstract: A 3-dimensional printed part can include a part body including a first matrix of fusing agent and thermoplastic polymer powder, a security feature including a second matrix of fusing agent, thermoplastic polymer powder, and photoluminescent agent, and a masking feature including a third matrix of fusing agent and thermoplastic polymer powder. The security feature can be positioned beneath and visible through the masking feature upon photoluminescent emission of the security feature.

Abstract: The present disclosure is drawn to 3-dimensional printed parts that can include a conductive composite portion and an insulating portion. The conductive composite portion can include a matrix of fused thermoplastic polymer particles interlocked with a matrix of sintered elemental transition metal particles. The insulating portion can include a matrix of fused thermoplastic polymer particles that are continuous with the matrix of fused thermoplastic polymer particles in the conductive composite portion. The insulating portion can be substantially free of sintered elemental transition metal particles and can include transition metal oxide bronze particles.

Abstract: A 3-dimensional printed part can include a part body including a first matrix of fusing agent and thermoplastic polymer powder, a security feature including a second matrix of fusing agent, thermoplastic polymer powder, and photoluminescent agent, and a masking feature including a third matrix of fusing agent and thermoplastic polymer powder. The security feature can be positioned beneath and visible through the masking feature upon photoluminescent emission of the security feature.

Abstract: The present disclosure is drawn to material sets for 3-dimensional printing. The material set can include a thermoplastic polymer powder having an average particle size from 20 ?m to 200 ?m, a conductive fusing agent composition including a transition metal, and nonconductive fusing agent composition. The nonconductive fusing agent composition can include transition metal oxide bronze particles.

Abstract: The present disclosure is drawn to material sets for 3-dimensional printing, 3-dimensional printing systems, and 3-dimensional printed parts. A material set can include a thermoplastic polymer powder having an average particle size from 20 ?m to 100 ?m, a photoluminescent ink including a photoluminescent agent, and a fusing ink. The fusing ink can include a fusing agent capable of absorbing electromagnetic radiation to produce heat.

Abstract: The present disclosure is drawn to three-dimensional printing kits, methods of making magnetic three-dimensional printed articles, and systems for three-dimensional printing. In one example, a three-dimensional printing kit can include a powder bed material, a fusing agent, and a magnetic agent. The powder bed material can include polymer particles. The fusing agent can include water and a non-magnetic radiation absorber. The non-magnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The magnetic agent can include a dispersion of magnetic nanoparticles.

Abstract: The present disclosure is drawn to fluid sets, material sets, and 3-dimensional printing systems. A fluid set can include a pretreat composition that includes a salt of an alkali metal with bromide or iodide. The fluid set can also include a conductive fusing agent composition including a transition metal for fusing thermoplastic powder when exposed to electromagnetic radiation.

Abstract: In an example method for forming three-dimensional (3D) printed electronic parts, a build material is applied. An electronic agent is selectively applied in a plurality of passes on a portion of the build material. A fusing agent is also selectively applied on the portion of the build material. The build material is exposed to radiation in a plurality of heating events. During at least one of the plurality of heating events, the portion of the build material in contact with the fusing agent fuses to form a region of a layer. The region of the layer exhibits an electronic property. An order of the plurality of passes, the selective application of the fusing agent, and the plurality of heating events is controlled to control a mechanical property of the layer and the electronic property of the region.

Abstract: According to examples, a method of making a three-dimensional conductive printed part, including forming a layer of polymeric build material; selectively applying a fusing agent on a first selected area of the formed polymeric build material; selectively applying a conductive agent on a second selected area of the formed polymeric build material; and applying a solder receiving material to a portion of the first selected area and a portion of the second selected area; in which the solder receiving material is present on a surface of the conductive three-dimensional printed part is disclosed.