The US patent system provides two types of patents to protect various types of ideas: design patents and utility patents. A design patent does not protect functionality; rather, it protects the “look and feel” of a product. Utility patents, on the other hand, protect inventions—whether completely new concepts or enhancements to old ones. The innovation might be a machine, a manufacturing technique, a novel composition or chemical compound, or a combination of these three. Nevertheless, utility patents may only be issued to innovations that meet certain conditions, and functioning is one of those criteria.
A utility patent may only be awarded for unique and useful discoveries; enhancements to prior inventions must also be non-obvious and significant in order to be eligible for patent protection. The concept of novelty is simple: it bans the patenting of existing or non-unique ideas and inventions. Nevertheless, most patent applications are rejected based on novelty rather than usefulness or functioning, thus doing a patent search will assist ensure that your idea is unique.