Arthur Thomas Bens

Non‐toxic flexible photopolymers for medical stereolithography technology

Purpose – To describe the development of a novel polyether(meth)acrylate‐based resin material class for stereolithography with alterable material characteristics.Design/methodology/approach – A complete overview of details to composition parameters, the optimization and bandwidth of mechanical and processing parameters is given. Initial biological characterization experiments and future application fields are depicted. Process parameters are studied in a commercial 3D systems Viper stereolithography system, and a new method to determine these parameters is described herein.Findings – Initial biological characterizations show the non‐toxic behavior in a biological environment, caused mainly by the (meth)acrylate‐based core components. These photolithographic resins combine an adjustable low Youngs modulus with the advantages of a non‐toxic (meth)acrylate‐based process material. In contrast to the mostly rigid process materials used today in the rapid prototyping industry, these polymeric formulations are ...

Ageing of acrylate‐based resins for stereolithography: thermal and humidity ageing behaviour studies

Purpose – The purpose of this paper is to describe the ageing behaviour of acrylate‐based resins for stereolithography (SL) technology using different test methods and to investigate these effects on polymers.Design/methodology/approach – Controlling the polymer degradation requires an understanding of many different phenomena, including the different chemical mechanisms underlying structural changes in polymer macromolecules, the influences of polymer morphology, the complexities of oxidation chemistry and the complex reaction pathways of polymer additives. Several ageing characterization experiments are given.Findings – The paper covers the ageing process analysis of acrylate‐based polymers. An overview of the ageing behaviour is given, along with the bandwidth of material characteristics for a prolonged lifetime of this material class.Research limitations/implications – For research and development in the field of rapid prototyping (RP) materials data about ageing behaviour and environmental effects ar...

Processing and mechanical properties of a new flexible acrylic stereolithographic resin family for engineering and medical device manufacturing

Stereolithography, as a well-known rapid prototyping process, has been used in a wide field of technical and also medical applications. Due to the stereolithography principle – the curing of a liquid photopolymer by a UV laser – the number of commercially available reaction mechanisms and related material characteristics is very limited. Our paper presents a novel class of non-toxic, biocompatible polyether(meth)acrylate-based resin formulations with outstanding flexible material characteristics. In contrast to the mostly rigid commercial engineering materials, these polymeric formulations are able to meet the demands for soft to stiff parts. Depending on the individual formulation, the cured resins can show a Youngs modulus from 25 MPa up to 1500 MPa. We give an overview over basic formulations and processing characteristics for this material class. Process parameters were studied in a commercial Viper Si² system (3D Systems); mechanical properties of different formulations were tested using standard tensile testing methods.

Novel, biocompatible polyether(meth)acrylate-based formulations for stereolithography – A new flexible material class for three-dimensional applications

Abstract Herein we present a novel polyether(meth)acrylate-based resin material for stereolithography and other photolithographic applications with outstanding flexible material characteristics. This group of photopolymeric resin products combines the advantages of a non-toxic (meth)acrylate-based process material with a broad spectrum of adjustable low Young’s modulus material characteristics. In contrast to the mostly rigid and non-flexible process materials used at the moment in the engineering world, these formulations are able to fulfil the extended need for a very flexible and also biocompatible engineering material, especially for threedimensional models or prototypes in the medical technology area. A short overview over the bandwidth of possible material characteristics is given in this publication.

Novel photosensitive polyurethanes based on photochromic dithienylethene monomers: synthesis, characterization and photophysical properties of a new film-building material for photonic applications

Abstract The synthesis of a novel photochromic dithienylethene-based polyurethane and its characterization by optical spectroscopy and scanning tunneling microscopy are presented. This linear polyurethane builds up perfect free-standing films suited for photonic applications. Moreover it may be extruded to long mechanically stable fibers. The photochromic reactions of the polyurethane, as being the electrocyclic ring-closure and ring-opening reactions of the dithienylethene unit in the polymer backbone, occur in a completely reversible and highly efficient fashion.