Final answer:
Robert Hooke made significant contributions to engineering by developing the microscope and describing the microscopic structures of cells.
Step-by-step explanation:
Robert Hooke made significant contributions to the field of engineering by developing the microscope. In his book Micrographia published in 1665, Hooke described microscopic structures and was the first to observe and describe cells in cork. This discovery revolutionized our understanding of the smallest unit of living things and laid the foundation for the development of the cell theory.