With the explosive development of decentralized finance (DeFi), we witness a phenomenal growth in tokenization of all kinds of assets, including equity, funds, debt, and real estate. By taking advantage of blockchain technology, digital assets are broadly grouped into fungible and non-fungible tokens (NFT). Here non-fungible tokens refer to those with unique and non-substitutable properties. Although the application of NFT is currently limited to digital fantasy artwork, games, collectible, etc., due to its unique capabilities, protocols, and platforms, they could be utilized in more practical issues. The main objective of this paper is to examine the requirements of presenting intellectual property assets, specifically patents, as NFTs. Hence, we offer a layered conceptual NFT-based patent framework with a comprehensive discussion on each layer, including storage, decentralized authentication, decentralized verification, Blockchain, and application layer. Furthermore, a series of open challenges about NFT-based patents and the possible future directions are highlighted. The proposed framework provides fundamental elements and guidance for businesses in taking advantage of NFTs in real-world problems such as grant patents, funding, biotechnology, event ticketing, and so forth.