Hexapod motion and positioning platforms have traditionally been used in engineering, optics, and physics applications for their ability to provide precision motion in all degrees of freedom and flexibility based on a programmable center of rotation. As hexapods become more mainstream, applications expand into medical fields as well. Dental biomechanics deals with the interactions between dental materials, treatment instruments or dentures and the reaction of teeth, biological tissues, etc. to mechanical stresses. A wide spectrum of force systems occur here with masticatory forces exerting loads to 380 N and torques to several Nm.
At the same time, movements of several orders of magnitude are involved: orthodontic equipment can change the position of teeth by up to several mm, whereas —during mastication— teeth are deflected by less than 100 µm and implants by as little as a few microns or less. These combinations of small forces with large deflections on the one hand, and large forces and extremely small deflections on the other, represent a challenge with respect to the biomechanical metrology.
To deal with this challenge, the Dental Clinic of the University of Bonn designed the HexMeS (Hexa- pod Measuring System) based on PI’s M-850 high load hexapod. The ability to move in all six axes in a highly stiff, small package, with resolutions of less than 1 µm (1 arcsec) was key reasons for choosing the hexapod motion system.