Abstract: An electromechanical motor, comprising a stator, including a drive unit and a frame portion, the frame portion holding the drive unit. The motor includes a shuttle adapted to be moved relative to the stator in a displacement direction, the shuttle movement being controlled by the drive unit and where the drive unit comprises at least one electromechanical drive element, extending along said displacement direction, and a drive body adapted to transfer a movement of the drive element onto the shuttle. The motor includes a sensor connected to the drive element and adapted to sense an electric or magnetic signal generated by the drive element in response to mechanical stress being applied to the drive element and to output a sensor signal.

Abstract: Golf club heads include: (a) a club head body having a ball striking face and defining a rear cavity; (b) a fluid-filled bladder in the cavity; and (c) a retaining member holding the fluid-filled bladder in the cavity. Other club heads include: (a) a club head body having a ball striking face and defining a rear cavity; and (b) an insert member in the rear cavity, wherein the insert member interior includes one or more chambers facing the rear surface of the ball striking face. The chamber(s) may cover at least 30% of a total surface area of the interior surface of the insert member and/or at least 30% of a total interior major surface area of the rear cavity. Golf clubs including these club heads and methods of making such golf clubs and golf club heads also are described.