Mechanical engineering is one of the oldest engineering disciplines. Traditionally concerned with harnessing and converting energy forms, mechanical engineers are inherently multi-disciplinary. For example, the design of a car engine combines the fields of chemistry, thermodynamics, heat transfer, fluid dynamics, electronic controls, dynamics and vibrations, materials science, and mechanical design. Although the mechanical engineer may specialize in one of these fields, a cursory knowledge of each of these fields is necessary to interact with other engineers. Mechanical engineers design machines, devices, various products and control systems, and work with the generation, conversion, transmission, and utilization of mechanical and thermal power. Assignments often include analysis and synthesis of mechanical, thermal, and fluid systems. Mechanical engineers are also responsible for characterization, specification, and analysis of materials used in design and manufacturing. Manufacturing systems, robotics, electromechanical devices, and control systems are also the purview of the mechanical engineer.