Adapting the surfaces of commercially available 3D printing resins for applications in separation science

Recent advances in additive manufacturing technologies have allowed 3D printing of polymers to flourish, resulting in many create-labs, and community creative-spaces for a wide variety of applications, using fused deposition modelling (FDM) and digital light projection (DLP) printer types. These printer types are attractive due to their low running cost, and relatively small footprint, allowing their use to be widespread1, 2. However, the challenge in adapting these materials in analytical science is still lagging. This is due to several factors such as ambiguous resin composition lists, non-standardised materials, printed surface artefacts, and inter-batch composition differences1-3. While creating a new resin type for specific applications is a logical approach to tailoring a specific surface, the process requires expertise, is application specific only, and is time consuming4, 5. Commercial resins have many components resulting in unknown or unpredictable surface chemistries. Having a standardised approach to material modification would rule out the possibility of unwanted side-reactions, or non-specific binding events when the materials are applied to analytical applications3, 6. One such example demonstrated the use of bare 3D printed resins for ion exchange chromatography of proteins, without any modifications3. Controlling the surface of these materials developed in 3D printing, allows the expansion of their application to analytical methods, and to the possibility of point-of-care diagnostics, remote diagnostics, and on-demand consumables for specific analyses. This work demonstrates several pathways taken to the surface modification of DLP resins, using physicochemical modification techniques such as plasma treatment, and coating technologies for controlled, tuneable surfaces. Materials were characterised using a variety of methods such as optical profilometry, FTIR, scanning electron microscopy, and validation using separation techniques.

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