ADDITIVE MANUFACTURING

Additive Manufacturing

Work in our lab has focused on using 3D printing methods such as select laser melting (SLM) to create bespoke devices to be produced efficiently and cost effectively for the treatment of aortic coarctation. Our first study has investigated using chemical etching to overcome design constraints associated with additive manufacturing and improving the overall surface finish. Using an SLM realizer (100W fibre laser) and Ti-6Al-4V powder, stent geometries can be printed when sufficient supports are placed. As shown by figure 1 and 2, it was demonstrated that more novel designs can be obtained by tailoring the initial .stl file input to have different initial dimensions, that can be removed by etching to create both closed / open cell designs and improve overall surface finish.

_{Figure (1): SLM printed stents and stereoscopic images showing (a) Simple honeycomb (SH) (b) Simple Honeycomb etched (SHE) and (c) the Novel Design Etched (NDE)}

_{Figure (2): SEM micrographs of honeycomb stents, showing the effect of chemical etching on surface cleaning and reduction of strut size. In as fabricated status (top row) and after etching (bottom row)}

Melt Electrowriting

Scale: 5mm

We are exploring using melt electrowriting (MEW) to develop bioinspired fibre-reinforcement structures for polymer-based prosthetic valve leaflets.

Reference: Hughes, C., Johnston, R., Whelan, A., O’Reilly, D., Campbell, E., Lally, C. (2023) ‘Using Finite Element Modelling to Inform Fibre Reinforcement in Polymer Heart Valve Leaflets’ in Bioengineering in Ireland Conference. Enfield, Ireland.

Publications

McGee, O. M., Geraghty, S., Hughes, C., Jamshidi, P., Kenny, D. P., Attallah, M. M., & Lally, C. (2022). An investigation into patient-specific 3D printed titanium stents and the use of etching to overcome Selective Laser Melting design constraints. Journal of the Mechanical Behavior of Biomedical Materials, 134. https://doi.org/10.1016/j.jmbbm.2022.105388