Working Principle of Sensor Chips
Sensor chips convert input physical quantities into electrical signals by utilizing specific physical effects or material properties. The following are the working principles of several common sensor chips:
Pressure Sensor
Pressure sensors are based on mechanical principles, measuring pressure by measuring the degree of elastic deformation of an object under force. They typically consist of piezoresistive, piezoelectric, or capacitive sensors. When subjected to external pressure, the resistance, charge, or capacitance within the sensor changes accordingly, generating an electrical signal.
Temperature Sensor
Temperature sensors utilize the temperature-sensitive properties of materials to measure ambient temperature. The most common types are thermistors and thermocouples. The resistance of a thermistor changes with temperature, while a thermocouple relies on the potential difference created by the temperature difference between different metals.
Optical Sensor
Optical sensors utilize the sensitivity of photosensitive materials to light signals to measure light intensity, light frequency, etc. Common optical sensors include photoresistors, photodiodes, and fiber optic sensors. When light shines on the sensor, its resistance, current, or voltage changes, thereby measuring light intensity or other optical parameters.
Accelerometer Sensors
Accelerometer sensors measure the acceleration of an object in space and are typically manufactured using microelectromechanical systems (MEMS) technology. They are based on the inertial effect of mass under force, detecting acceleration by measuring minute displacements or electrostatic effects. These sensors can be used in devices such as automotive safety systems, smartphones, and game controllers.
Gas Sensors
Gas sensors are used to detect the concentration of gases in the environment. They are typically based on chemical reaction principles, measuring the presence and concentration of a target gas through sensitive materials that interact with it. For example, electrochemical sensors utilize redox reactions to detect gas concentration, while optical sensors utilize effects such as absorption, scattering, or luminescence.
