Multi-dimensional Structuring of Native Silk

The development of silk processing techniques has enabled us to benefit from this superior natural material, not only in its spun form as a fibre but also as a rehydrated protein solution which can then be converted into countless shapes, structures and designs. To date, all non-textile silk-based structuring techniques use rehydrated silk proteins, yet, it is well known that the process of regeneration/reconstitution results in materials that lack the mechanical integrity present in its native silk source. This highlights a key gap in current silk fabrication research, leaving native silk unexplored. In this thesis, I explore the suitability of native Bombyx mori silk for the fabrication of 1D lines, 2D patterns and 3D scaffolds using three novel structuring pathways namely photocuring (1D, 2D) and emulsification (3D). This thesis demonstrates that native silk is a suitable material for successful fabrication of highly detailed 1D and 2D hydrogel patterns which have the potential for a broad range of applications. Moreover, native silk is found to be superior to the current state of the art reconstituted silk. Despite this, native silk was found to be not suitable for 3D fabrication, being outperformed by high-quality reconstituted silk when making 3D structures due to the high sensitivity of native silk to the shear applied during the fabrication process. By exploring the rheological behaviour of native and reconstituted silks, it was found that avoiding silk degumming, can significantly improve the pattern quality making it comparable to the native protein allowing scaling up of the process for industrial use. Finally, I believe that the insight into the differences between native and reconstituted proteins together with the exploration of structure formation mechanism and properties can inspire future silk fabrication.