What is the String Theory?
It is a very vast and ultra-complicated theory which cannot be explained in a single answer. Though I'll try to introduce the concept of string like entities to arouse your interest to learn about the theoretical formulations in detail.
The atom of all matter consists of a dense positively charged nucleus and electrons moving in incessant motion around them in various discrete quantum states.
The nucleus is made up of protons and neutrons which are glued together by a special type of gauge boson which is the carrier of strong interaction and is called a gluon.
Further, the nucleons (neutrons and protons) are build up of three quarks which carry fractional charge and spin.
The quarks themselves are not elementary and are supposed to be formed of string like entities.
The underlying theory is not very concrete and is yet to attain firm footing.
Perhaps you could make such an advance in the string theory. Who knows :P :D