Characterisation of Epoxy Resins for Microstereolithographic Rapid Prototyping

Two epoxy resins are investigated using non-degenerate fourwave mixing. The materials assessed are optimised for use with a UV argon-ion laser. The holographic gratings were written at a wavelength of l= 351.1 nm for an irradiance range 0.5–3.0 W/cm 2 and read at l= 632.8 nm in order to compare the reactivity, curing speed, shrinkage and resolution of the resins. These experiments were carried out to prove the suitability of the photopolymerisation systems for use with a new microstereolithographic technique. This new technique exploits a spatial light modulator to create 3D components using a completely planer, layer-by-layer, process of exposure which is described herein. With this procedure it is possible to build components with dimensions in the range of 50 mm to 50 μm, and feature sizes as small as 5 μm with a resolution of 1 μm.