The complex protein and fiber structure of wool inspired us to find a way to grow wool without sheep. We utilize tissue engineering to grow wool Hair Follicle Germ (HFG) cells on microfluidic devices designed to provide the cells with nutrients and remove waste. The subsequent wool could then be harvested and processed or remain on the microfluidic device. This approach could expand outside of sheep wool and apply to other keratin-based structures such as fur and feathers. Growing colored, keratin-based fibers of different grades could also occur and be produced without the risk and expense of growing and modifying an entire organism.