With very limited exceptions, there is no statutory requirement to prototype your invention provided the written patent application discloses the invention in sufficient detail to enable one of “ordinary skill” in the relevant art to reproduce the invention without “undue experimentation.”
The execeptions would include certain therapeutic drugs or variations of compositions that produce new and unexpected results. In those cases, the U.S. Patent & Trademark Office (PTO) may require test data. A perpetual motion invention may also require the submission of a prototype to the PTO.