What is a Sensor?
Sensors can be found in almost every electronic device today. The number of sensors in our everyday life is growing rapidly - whether in medical technology, smartphones or in the emerging field of autonomous driving. There is a huge variety of sensors available that complement or enhance the human senses of hearing, smell, taste, sight and touch.
In the world of electronics, a sensor is seen as the interface between the circuit and its environment. One of the characteristics of silicon as a semiconductor material, is its ability to convert light radiation into electrical voltage. This property is used in photovoltaics to generate electricity. In microelectronics both transistors and photodiodes can be integrated on the silicon wafer as equal circuit elements. An optical coating on the wafer surface above the finished circuit allows sensors to identify colors, ultraviolet or infrared light. The sensor can thus become part of the integrated circuit, with all the advantages of microelectronics: small, robust, inexpensive and mass producible.