Infrared-light induced curing of photosensitive resins through photon up-conversion for novel cost-effective luminescent 3D-printing technology

Abstract

Cost-effective luminescent 3D-printing technology approach through infrared-laser-induced photon up-conversion in rare-earth-doped materials for “laser-writing” of luminescent 3D printed structures and envisioned applications in nano-photolithography.

Upconversion‐Nanoparticle‐Assisted Radical Polymerization at λ=974 nm and the Generation of Acidic Cations

“…The use of UCNPs to generate UV initiator systems based on benzophenone (BP) also resulted in larger curing thicknesses. Recently, the combination of high‐intensity UV/blue‐emitting microcrystals with the radical photoinitiator bis(2,4,6‐trimethylbenzoyl)‐phenylphosphineoxide (Irgacure 819) was applied for 3D printing . To the best of our knowledge, no reports have been published yet regarding photolytic formation of acidic cations with UCNPs and photoredox systems working in the UV spectral region.…”

“…This light might be absorbed by a highly sensitive visible photoinitiator system whose absorption remains between λ =500–600 nm. In general, such visible‐light‐based radical photoinitiators efficiently sensitise the generation of radicals comprising eosin and an amine . Those visible systems also work well by direct excitation with green light .…”

Near‐Infrared Photoinduced Reactions Assisted by Upconverting Nanoparticles

“…An ECM provides structural and biochemical support to the surrounding cells and is an ideal cell culture medium. However, the reported UCNP‐assisted photopolymerizations were based on photoinitiated radical polymerizations . However, radicals and reactive species may damage biological components and living cells in an ECM, which hinders biomedical applications of UCNP‐assisted photopolymerization.…”

“…A field that awaits exploration is the combination of upconversion technology with photochemically driven 3D additive manufacturing technologies such as direct laser writing (DLW). At the moment, 3D photopolymerization based on photon upconversion only showed submillimeter spatial resolution . The intrinsic problem for high‐resolution 3D UCNP‐assisted polymerization is that the saturation in the upconversion process reduces its spatial resolution .…”

Upconversion enhancement in NaYF4:Yb3+, Er3+ crystal via Bi3+ doping

“…UC materials are widely used in the fields of biological imaging [2] , 3D printing [3] , sensors [4] and solar cell [5] because of their good chemical stability, optical stability and less toxicity. However, the low efficiency of conversion hinders its further development [6] .…”