Force sensors are mainly classified into several types according to their measurement principle and measurement dimension, each suitable for different application scenarios.
Classification by Measurement Principle
Strain Gauge Force Sensors: Based on the resistance strain effect of metal or semiconductor materials, where the resistance changes with deformation, the resistance change is converted into a voltage signal using a Wheatstone bridge. These sensors have a mature structure, moderate cost, and are widely used in electronic scales, industrial weighing, and other applications.
Piezoelectric Force Sensors: Utilizing the piezoresistive effect of semiconductor materials (such as single-crystal silicon), i.e., stress causes a change in resistivity, they have high sensitivity, are easy to miniaturize, and are commonly used in MEMS sensors and high-precision equipment.
Piezoelectric Force Sensors: Based on the piezoelectric effect of materials such as quartz and lead zirconate titanate, they generate an electric charge when subjected to force. Suitable for dynamic force measurement (such as impact and vibration), but unable to detect static forces, they are commonly used in automotive crash testing and mechanical impact monitoring.
Capacitive force sensors: These sensors measure the change in capacitance caused by the change in distance between two parallel conductor plates due to force. They offer advantages such as high sensitivity, low power consumption, and strong anti-interference capabilities, making them suitable for high-precision static measurement environments.
Optical force sensors: These sensors utilize the bending or refractive index changes in optical fibers under stress, which affect light intensity, phase, or polarization. Force is indirectly measured by detecting changes in the optical signal. They are resistant to electromagnetic interference and suitable for special environments such as medical endoscopes and aerospace applications.