Microfluidic extrusion

A method for producing a biopolymer fiber comprising:

• dissolving collagen in an acid solution to form a collagen solution;
• extruding the collagen solution through a first needle;
• passing the extruded collagen solution through a fibril-forming bath;
• drawing the fiber at a draw ratio between about 1.5 and about 3 relative to the extrusion speed;
• dehydrating the drawn fiber in a dehydration bath;
• and
• crosslinking the dehydrated fiber with a crosslinker.

A method for producing a bundle of biopolymer fibers comprising:

• simultaneously extruding multiple collagen solutions through multiple needles;
• passing the extruded solutions through a fibril-forming bath;
• drawing the resulting fibers at a draw ratio between about 2 and about 4 times relative to the extrusion speed;
• collecting the drawn fibers as a bundle;
• and
• crosslinking the bundle.

A method for producing a biopolymer fiber comprising:

• dissolving collagen in an acidic solution;
• degassing the collagen solution;
• centrifuging the degassed solution;
• extruding the centrifuged solution through a needle directly into a fibril-forming bath;
• drawing the resulting fiber at a speed between about 2 to about 4 times faster than the extrusion speed;
• and
• crosslinking the drawn fiber.