meet4108:
Can I patent self made Arduino shields??
If it meets all the requirement of the patent office and you can afford the process required to go through, I guess you could. Better to just rely on copyright and trademark protections and don't publish the source code or design files. While that is not in the spirit of the open source Arduino world, you are free to release proprietary products it you wish and hope that the world beats a path to your door.
Lefty