Abstract: The present disclosure provides methods of three-dimensional printing, including iteratively applying individual build material layers of polyamide particles and selectively applying a fusing agent onto the individual build material layers to form individually patterned object layers. The fusing agent can include water and a radiation absorber. The method can also include selectively applying a pore-promoting agent onto the individual build material layers at some or all of the individually pattered object layers to form a pore-generating region, and iteratively exposing the individual build material layers to electromagnetic energy to generate molten polymer from polyamide particles in contact with the radiation absorber that upon cooling forms fused polymer body. A material used to form the fused polymer body without pores can exhibit a material dielectric permittivity, and the fused polymer body at a location that includes the pores can exhibit a decreased dielectric permittivity.

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: A materials kit for three-dimensional (3D) printing can include a powder bed material including electroactive polymer particles including electroactive polymer having a melting temperature from about 100° C. to about 250° C. and a fusing agent including a radiation absorber to selectively apply to the powder bed material.

Abstract: In one example in accordance with the present disclosure, a three-dimensional (3D) printed sensor system is described. The 3D printed sensor system includes a 3D printed object. The 3D printed sensor system also includes a 3D printed sensor on a body of the 3D printed object. The 3D printed sensor includes a dielectric region disposed between electrodes. A capacitance of the dielectric region is indicative of an environmental condition of the 3D printed object. The 3D printed sensor system also includes a controller integrated with the body of the 3D printed object. The controller is to measure a capacitance of the 3D printed sensor.

Abstract: The present disclosure relates to a build composition for a 3-dimensional printing process. The build composition comprises thermoplastic polymer particles, a first photoluminescent agent and a second photoluminescent agent. The build composition has a spectral signature characteristic of the presence of the first photoluminescent agent and the second photoluminescent agent in combination.

Abstract: The present disclosure relates to a build composition for a 3-dimensional printing process. The build composition comprises thermoplastic polymer particles, a first photoluminescent agent and a second photoluminescent agent. The build composition has a spectral signature characteristic of the presence of the first photoluminescent agent and the second photoluminescent agent in combination.

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: 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, 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: A multi-fluid kit for three-dimensional printing can include a fusing agent and a nanoparticle-containing agent. The fusing agent can include water and a radiation absorber, where the radiation absorber absorbs radiation energy and converts the radiation energy to heat. The nanoparticle-containing agent can include a liquid vehicle, high density nanoparticles, and a nanoparticle suspension compound selected from the group consisting of terpineol, ethyl cellulose, and a combination thereof.

Abstract: The present disclosure relates a method of 3-dimensional printing a printed part. The method comprises printing an inkjet dopant composition at selected locations on a layer of build material comprising polymer particles. The inkjet dopant composition comprises a dopant dispersed or dissolved in a liquid carrier. Polymer particles at selected areas of the layer of build material are then fused to form a fused polymer layer comprising the dopant. The selected areas of the layer of build material include areas of the layer of build material that have not been printed with the inkjet dopant composition.

Abstract: The present disclosure relates a method of 3-dimensional printing a printed part. The method comprises printing an inkjet dopant composition at selected locations on a layer of build material comprising polymer particles. The inkjet dopant composition comprises a dopant dispersed or dissolved in a liquid carrier. Polymer particles at selected areas of the layer of build material are then fused to form a fused polymer layer comprising the dopant. The selected areas of the layer of build material include areas of the layer of build material that have not been printed with the inkjet dopant composition.

Abstract: The present disclosure relates a method of 3-dimensional printing a printed part. The method comprises printing an inkjet dopant composition at selected locations on a layer of build material comprising polymer particles. The inkjet dopant composition comprises a dopant dispersed or dissolved in a liquid carrier. Polymer particles at selected areas of the layer of build material are then fused to form a fused polymer layer comprising the dopant. The selected areas of the layer of build material include areas of the layer of build material that have not been printed with the inkjet dopant composition.

Abstract: A materials kit for three-dimensional (3D) printing can include a powder bed material including electroactive polymer particles including electroactive polymer having a melting temperature from about 100° C. to about 250° C. and a fusing agent including a radiation absorber to selectively apply to the powder bed material.

Abstract: The present disclosure relates to a build composition for a 3-dimensional printing process. The build composition comprises thermoplastic polymer particles, a first photoluminescent agent and a second photoluminescent agent. The build composition has a spectral signature characteristic of the presence of the first photoluminescent agent and the second photoluminescent agent in combination.

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: Optical readers are disclosed in examples herein. An example optical reader including a light source to emit a light beam; and a spot pattern generator to receive the light beam and to generate a two-dimensional spot array from the light beam, the two-dimensional spot array to be directed toward a substrate having nanostructures, the two-dimensional spot array to be sensed to detect a presence or an absence of a substance of interest on the substrate.

Abstract: Optical readers are disclosed in examples herein. An example optical reader including a light source to emit a light beam; and a spot pattern generator to receive the light beam and to generate a two-dimensional spot array from the light beam, the two-dimensional spot array to be directed toward a substrate having nanostructures, the two-dimensional spot array to be sensed to detect a presence or an absence of a substance of interest on the substrate.

Abstract: Optical readers are disclosed in examples herein. An example optical reader including a light source to emit a light beam; and a spot pattern generator to receive the light beam and to generate a two-dimensional spot array from the light beam, the two-dimensional spot array to be directed toward a substrate having nanostructures, the two-dimensional spot array to be sensed to detect a presence or an absence of a substance of interest on the substrate.

Abstract: Molecule sensing apparatus. The apparatus has first and second chambers, an input port extending into the first chamber, a fluid channel extending from the first chamber to the second chamber, and a surface-enhanced substrate in the second chamber.