Power toothbrush using a shear thickening fluid

Abstract From the Canadian patent

The combination of a power toothbrush and an oral fluid in which the oral , fluid has the characteristic of changing viscosity depending upon the action , of a workpiece element portion such as a flexible membrane, of the power toothbrush. The power toothbrush has two operating conditions. In one condition, the membrane moves toward and away from the teeth at a speed such that the fluid is liquid and flows easily to and around the teeth including , the interproximal regions. In the second condition the membrane is moved at a , significantly higher speed in response to which the viscosity of the fluid increases substantially, having a shear rate at least as great as necessary to remove …