Knowledge of the nail structure will enable you to identify the condition of the nail. You will need to identify whether a nail is healthy or unhealthy. You will also need to know which parts of the nail are responsible for growth, protection, nail shape and size.
Learning to know and recognize the Anatomy of the Nail is very important, whether for those who work in the Nails sector and every day must take care (even if only Aesthetically) of the Nails of their Customers, and for those who are simply passionate to the topic or prefer to independently take care of their Hands and Feet!
I need more information to even know where to get started with this. What kind of art? Painting? Sculpture? Writing? Spoken word poetry? This is a very broad "thesis", and unfortunately I'm pretty sure it doesn't qualify as a thesis at all.