Co-Current Device for Synthesis of Spider Silk

Spider silk is a material that is has proven to have many applications in fields of Surgery, and Bioengineering. It has been shown to be bio- inert, allowing for use in physiological environments, as well as having unique and valuable mechanical characteristics allowing new uses in engineering and surgery as devices such as sutures or implants. Unfortunately there are no feasible ways to farm natural silk, making artificial synthesis of the material a very important research topic. Artificial silk synthesis involves expressing silk in bacteria and then purifying it. This purified silk must be concentrated in order to yield fiber. The silk is dehydrated, then dissolved it in a volatile solvent, creating a concentrated dope. Modern spinning involves pushing silk dope through a simple needle, allowing the shear forces of the needle to form the silk. This traps pockets of solvent in the fiber, weakening the fiber’s mechanical properties. Utilizing microfluidics, a novel approach has been developed which involves the co-current of the silk dope with a buffer, allowing diffusion of the solvent present in the dope into the buffer, while also allowing the shear forces of the buffer to form the silk, thus allowing for a stronger silk fiber. This co- current device allows the flow of a buffer to surround the silk dope, allowing them both to be present in the state of laminar flow. This forces the substances to interact just through the mode of diffusion, thus allowing the removal of solvent pockets, and thereby improving the mechanical properties.