Drivetrain assemblies for generating power tapping motion using flexures

Drivetrain assemblies for personal care devices to generate controllable power tapping motion alone or with controllable sweeping motion. The drivetrain assemblies include a drivetrain shaft at least partially contained within a body portion. The drivetrain shaft is further configured to engage a brush head member. Some drivetrain assemblies include a single actuator for generating periodic linear movement, wherein the drivetrain shaft transmits the linear movement to the brush head member via a pivoting motion and/or a translational motion. Other drivetrain assemblies include the actuator for generating periodic linear movement and a motor on the drivetrain shaft to periodically rotate the shaft about a central axis. Still other drivetrain assemblies include a motor to rotate the drivetrain shaft about the central axis, an actuator to generate periodic linear movement, parallel flexible flexures to constrain the periodic linear movement, and parallel substantially rigid translation linkages to transmit the periodic linear movement.