This review surveys relevant scientific papers and patents on the development of crosslinked epoxies and also photo-curable polymers based on multifunctional acrylates with improved toughness.

In this study, a new process for additive manufacturing (AM) of dense and strong ceramic objects is described. The lithography‐based ceramic manufacturing (LCM) technique is based on the selective curing of a photosensitive slurry by a dynamic mask exposure process. The LCM technique is able to produce strong, dense and accurate alumina ceramics without virtually any geometrical limitations. With over 99.3% of a theoretical alumina density, four‐point bending strength of 427 MPa, and very smooth surfaces, the LCM process distinguishes itself from other AM techniques for ceramics and provides parts with very similar mechanical properties as conventionally formed alumina.

The first example of the fabrication of complex 3D polymer-derived-ceramic structures is presented with micrometer-scale features by a 3D additive manufacturing (AM) technology, starting with a photosensitive preceramic precursor. Dense and crack-free silicon-oxycarbide-based microparts with features down to 200 μm are obtained after pyrolysis at 1000 °C in a nitrogen atmosphere.

Lithography based additive manufacturing technologies (AMT) like stereolithography or digital light processing have become appealing methods for the fabrication of 3D cellular scaffolds for tissue engineering and regenerative medicine. To circumvent the use of (meth)acrylate-based photopolymers, that suffer from skin irritation and sometimes cytotoxicity, new monomers based on vinyl esters were prepared. In vitro cytotoxicity studies with osteoblast-like cells proofed that monomers based on vinyl esters are significantly less cytotoxic than (meth)acrylates. Photoreactivity was followed by photo-differential scanning calorimetry and the mechanical properties of the photocured materials were screened by nanoindentation. Conversion rates and indentation moduli between those of acrylate and methacrylate references could be observed. Furthermore, osteoblast-like cells were successfully seeded onto polymer specimens. Finally, we were able to print a 3D test structure out of a vinyl ester-based formulation by l-SLA with a layer thickness of 50 lm. For in vivo testing of vinyl esters these 3D scaffolds were implanted into surgical defects of the distal femoral bone of adult New Zealand white rabbits. The obtained histological results approved the excellent biocompatibility of vinyl esters. V V C 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6941-6954, 2009

In recent days, additive manufacturing technologies (AMT) based on photopolymerization have also found application in tissue engineering. Although acrylates and methacrylates have excellent photoreactivity and afford photopolymers with good mechanical properties, their cytotoxicity and degradation products disqualify them from medical use. Within this work, (meth)acrylate‐based monomers were replaced by vinyl esters with exceptional low cytotoxicity. The main focus of this paper lies on the determination of the photoreactivity and investigations concerning mechanical properties and degradation behavior of the new materials. Tested monomers provide sufficient photoreactivity for processing by AMT. Mechanical properties similar to natural bone could be obtained by adding suitable fillers like hydroxylapatite (HA). The right ratio of hydrophobic and hydrophilic monomers allows the tuning of the degradation behavior. Finally, with the optimum formulation, cellular 3D structures were built using digital light processing. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.