instruction: Please give me a short bulleted list of the principal fields of engineering
context: Main branches of engineering
  For a topical guide, see Outline of engineering.
  
  Hoover Dam
  Engineering is a broad discipline that is often broken down into several sub-disciplines. Although an engineer will usually be trained in a specific discipline, he or she may become multi-disciplined through experience. Engineering is often characterized as having four main branches: chemical engineering, civil engineering, electrical engineering, and mechanical engineering.
  
  Chemical engineering
  Main article: Chemical engineering
  Chemical engineering is the application of physics, chemistry, biology, and engineering principles in order to carry out chemical processes on a commercial scale, such as the manufacture of commodity chemicals, specialty chemicals, petroleum refining, microfabrication, fermentation, and biomolecule production.
  
  Civil engineering
  Main article: Civil engineering
  Civil engineering is the design and construction of public and private works, such as infrastructure (airports, roads, railways, water supply, and treatment etc.), bridges, tunnels, dams, and buildings. Civil engineering is traditionally broken into a number of sub-disciplines, including structural engineering, environmental engineering, and surveying. It is traditionally considered to be separate from military engineering.
  
  Electrical engineering
  Main article: Electrical engineering
  
  Electric motor
  Electrical engineering is the design, study, and manufacture of various electrical and electronic systems, such as broadcast engineering, electrical circuits, generators, motors, electromagnetic/electromechanical devices, electronic devices, electronic circuits, optical fibers, optoelectronic devices, computer systems, telecommunications, instrumentation, control systems, and electronics.
  
  Mechanical engineering
  Main article: Mechanical engineering
  Mechanical engineering is the design and manufacture of physical or mechanical systems, such as power and energy systems, aerospace/aircraft products, weapon systems, transportation products, engines, compressors, powertrains, kinematic chains, vacuum technology, vibration isolation equipment, manufacturing, robotics, turbines, audio equipments, and mechatronics.
  
  Bioengineering
  Main article: Biological engineering
  Bioengineering is the engineering of biological systems for a useful purpose. Examples of bioengineering research include bacteria engineered to produce chemicals, new medical imaging technology, portable and rapid disease diagnostic devices, prosthetics, biopharmaceuticals, and tissue-engineered organs.
response: chemical engineering, civil engineering, electrical engineering, mechanical engineering and bioengineering