A radiation-curable ink jet composition includes vinyl methyl oxazolidinone and a vinyl ether group-containing (meth)acrylate represented by the following formula (1):

H.sub.2CCR.sup.1COOR.sup.2OCHCHR.sup.3

(where, R.sup.1 is a hydrogen atom or a methyl group, R.sup.2 is a divalent C2-C20 organic residue, and R.sup.3 is a hydrogen atom or a monovalent C1-C11 organic residue).

An ink jet printing apparatus includes a radiation-curable ink having a surface tension of 25.0 mN/m or less, and a printing head including a nozzle face having an opening of a nozzle through which the radiation-curable ink is ejected, and a liquid-repellent film on the nozzle face. The liquid-repellent film enables the radiation-curable ink to forms a contact angle of 60.0 degrees or more therewith.

An ink set of radiation curable ink jet inks each of which contains polymerizable compounds, includes a color ink and a clear ink, the polymerizable compounds contained in the clear ink include a monomer A having a hydroxy group and a monomer B having a volume of 0.26 nm.sup.3 or more and a height direction area of 0.25 nm.sup.2 or more with respect to a long side each of which is defined by the Van der Waals radii, and a total content of the monomer A and the monomer B is 80 percent by mass or more with respect to a total mass of the polymerizable compounds contained in the clear ink.

An ink set of radiation curable ink jet inks each of which contains polymerizable compounds, includes a color ink and a clear ink, the polymerizable compounds contained in the clear ink include a monomer A having a hydroxy group and a monomer B having a volume of 0.26 nm.sup.3 or more and a height direction area of 0.25 nm.sup.2 or more with respect to a long side each of which is defined by the Van der Waals radii, and a total content of the monomer A and the monomer B is 80 percent by mass or more with respect to a total mass of the polymerizable compounds contained in the clear ink.

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to gel-phase inks suitable for extrusion-based 3D printing and methods of making the same, as well as anisotropic hydrogels printed from the same. In another aspect, the disclosure relates to linear contractile elements constructed from the anisotropic hydrogels and 3D structures with programmed morphologies and motions comprising the linear contractile elements. In still another aspect, the disclosure relates to a process for preparing soft materials and a method to create 3D structures starting from the gel-phase inks disclosed herein. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to gel-phase inks suitable for extrusion-based 3D printing and methods of making the same, as well as anisotropic hydrogels printed from the same. In another aspect, the disclosure relates to linear contractile elements constructed from the anisotropic hydrogels and 3D structures with programmed morphologies and motions comprising the linear contractile elements. In still another aspect, the disclosure relates to a process for preparing soft materials and a method to create 3D structures starting from the gel-phase inks disclosed herein. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

An active-energy-ray-curable composition including a pigment, a polymerizable compound, and a pigment-adsorptive component is provided. The pigment is at least one selected from the group consisting of strontium titanate, calcium titanate, zinc sulfide, and zinc oxide. The polymerizable compound contains an acrylamide compound (A1) having a specific ester structure.

An active-energy-ray-curable composition including a pigment, a polymerizable compound, and a pigment-adsorptive component is provided. The pigment is at least one selected from the group consisting of strontium titanate, calcium titanate, zinc sulfide, and zinc oxide. The polymerizable compound contains an acrylamide compound (A1) having a specific ester structure.

The present invention includes a system, apparatus and method for generating a three-dimensional image and/or printing a three dimensional structures, the system comprising: a medium comprising a photocurable monomer and an optical molecular switch molecule that has a non-fluorescent state and a fluorescent state, wherein the monomer forms a polymer upon exposure to the emitted light. Also taught are novel fluorescent photoswitch molecules.

The present invention includes a system, apparatus and method for generating a three-dimensional image and/or printing a three dimensional structures, the system comprising: a medium comprising a photocurable monomer and an optical molecular switch molecule that has a non-fluorescent state and a fluorescent state, wherein the monomer forms a polymer upon exposure to the emitted light. Also taught are novel fluorescent photoswitch molecules.