Force measurement system for invisalign based on thin film single force sensor

To measure the forces delivered by invisaligner, a force measurement system for invisalign based on thin film single force sensor was designed and established. Firstly, invisaligners with different thicknesses and different lingual activations at upper left central incisor were designed and fabricated. In order to eliminate the effects of the thickness of sensors and other pastes, a 3D light-cured resin model was specially designed and made, as experiment model. A numerical model including teeth and invisaligner was built up to simulate the process of invisalign. Then, the force measured system including flex pressure sensor, signal acquisition circuit board and computer was established to measure the force delivered by the invasilgners. Finally, the simulation results were compared with the experimental results. The simulation results and real experimental results are nearly consistent under different activations and different material thicknesses, and the force error is less than 0.2 N. So a force measurement system for invisalign was established during orthodontic treatment.