Robert Hooke has a number of inventions and patents to his credit. One of his most notable and useful inventions is the balance spring, which is a timepiece component that allows watches to remain accurate and remains widely used today.
Hooke's work as an experimental scientist led to his invention of the universal joint and the iris diaphragm, and he secured patents in the field of optics and elasticity. Hooke is said to have also made contributions to gravity theory, and he created the theory of elasticity, more commonly known as "Hooke's Law." Through his work in microscope observation, Hooke was the first to have observed plant cells and, as a result, is credited with coining the scientific term "cells." In addition to his work in science, Hook was also an philosopher and an architect making advances in surveying.