There is no need to patent an invention in order to use it. Just keep in mind that it can be used only if no one else has already patented it. What is more, if you don’t have a patent, you have no protection for your invention and other people may be able to use or copy it. Furthermore, once you disclose your unpatented invention to the public you will no longer be able to seek for protection of the same and others will be able to copy it.