Scalable R2R Processing of Regenerated Silk Fibroin Film

Owing to its tunable physical, chemical, and biological properties, regenerated silk fibroin (RSF) has been studied extensively in the film format for potential use in many applications, namely drug delivery, medical/environmental diagnostics, electronics, optics, and tissue engineering. Methods such as spin coating and drop casting are routinely employed to create films from RSF solution in the laboratory for research sample production. However, these techniques do not necessarily translate to larger scales without considerable waste or inconsistency, potentially limiting widespread adoption of useful engineering devices developed from RSF. Meanwhile, techniques developed to produce films industrially such as roll-to-roll (R2R) processing are utilized to manufacture large areas of sensitive coatings and intricate devices, such as microfluidics and flexible solar panels. Herein, we present the development of a scalable means of producing RSF films employing techniques from R2R manufacturing using aqueous processing of RSF. This includes the optimization of RSF-inks that are conducive to solution coating and the comparison of knife-blade sheet-coating at the laboratory scale and slot die R2R coating at multi-meter production scale. This work demonstrates that scalable production is possible for widespread adoption of RSF-based functional devices.