3D printable inter cross-linking network (ICN) gels for reversible transparency control with water content

Abstract

A patient-specific phantoms, which are equivalent to human tissues, is needed in the experimental dosimetric verification before radiotherapy treatments. Most of the shape of gel phantoms have been structurally limited because of the fabrication method using mold technique. The present study focuses on direct freeform fabrication of gel phantom with the customized optical 3D gel printing system. Life-sized gel phantoms were replicated using conventional mold techniques, the 3D printer with two-step sequential free-radical polymerization process and inter cross-linking network gels as 3D printing materials. The gel phantoms are ultraviolet light-sensitive instead of radiation. The ultraviolet sensitivity of the gel phantoms (using mold techniques) with different molar ratios were experimentally evaluated with transmittance measurements, and were theoretically estimated by curve fitting to the observed data. This measurement gave us the insight that more vinyl monomers in the gel phantoms caused rapid polymerization and visibly opaque as well as conventional gel dosimeters. We confirmed that inter cross-linking network gel was 3D printable with the customized 3D printer, with resolution of fabrication 500 lm, as pre-finger-shaped phantom. The cross section of 3D printed gel phantom showed the distribution of opacity, that is, the distribution of UV irradiation. We expect that the 3D printer specialized gel materials and ICN gels are feasible for practical fabrication method of 3D gel phantom.

Flexible and Conductive 3D Printable Polyvinylidene Fluoride and Poly(N,N‐dimethylacrylamide) Based Gel Polymer Electrolytes

“…3D printing systems have made it possible to make flexible, gel like structures to be free formed in customized sizes and shapes and thus offer numerous scopes in applied sectors. [ 19 ] Previously, our research group has successfully fabricated various types of 3D printed soft materials using customized 3D printers such as inter crosslinking network gels for gel phantom model, [ 20 ] highly robust thermoresponsive shape memory gels for soft robotics, [ 21,22 ] and ionic liquid‐based conductive gels and nanocomposites for electrochemical devices through a moldless process. [ 23,24 ]…”