Interesting, but as I see it you’d still need an unlimited supply of DP cells and activated stem/progenitor cells in order to make the follicle cycle. I think these can’t just be 3D printed that easily because the problem is creating working duplicates with the right genes activated. A 3D printer can’t ensure that the right genes are activated. It’s more of a way to position all the components in their proper places X number of times.
As far as as using a 3D printer to produce follicles, I think it could work (in theory) as long as you had an unlimited supply of working DP and stem cells, but how do you get those cells? A 3D printer can’t manufacture the components, only a structure made up of the components.
One other thing: I believe there is a young medical researcher in Canada who recently won an award for inventing a 3D printer that can make skin (including hair) for people like burn victims. I saw an article on it, I’ll try to find it. But I think when it came time for “proving” the device could actually make skin with growing hair, they basically said more research and development are needed.