INTRODUCTION
Many new inventions and engineering designs today focused on solving man-machine interface. Combining with the latest developments in expert system, fuzzy logic and neural networks application, sensor technology helps the system to capture data and inputs most needed by the expert system. Enhancing the sensor performance will improve tremendously the ability of the system. Therefore, understanding sensor technology is utmost important for engineers and designers. Sensor technology is one of the basic components of any smart system. Engineers and designers should able to grasp the technology for future developments in engineering design.