Research on a Novel Sensor for Measuring Force in Arbitrary Direction

A new kind of sensor for measuring force in arbitrary direction to test force´s value and direction with a dimension Oslash53 mm times h8.2 mm, developed for dental surgery measurement, has been proposed in this article. A four-beam structure is employed for arbitrary force test. Based on material theory the value and direction of force can be calculated by strain test. A matrix that proves the four-beam sensor feasibility has been deduced with the relation between the force and strain. FEM (finite element analysis method) is adopted to simulate the sensor´s displacement characteristics under different force, which shows the necessity of two-layer spring. Chemical etch processing method is applied to manufacture the two-layer spring with thickness 0.1 mm and spacer parts with thickness 0.2 mm. Then the experimental system including the novel sensor, the calibrating force gauge and data acquisition system is constructed. Experiment results with high linearity and low noise in the range of 0.2 N-0.4 N have been obtained. The novel sensor´s sensitivity is 0.04 N^-1 in x direction, z direction and 0.02 N^-1 in y direction. Experiments show that the sensor meets practical using demands in dental surgery field.