Embodiments of the present invention relate to an improved stimulation device. Embodiments of the improved stimulation device includes a cup and a driver. The cup has a cavity surrounded by a rim. The driver comprises a plate disposed on an underside of the cup, a cam disposed adjacent to the plate, and a motor mechanically coupled to the cam. The driver comprises a cam pin affixed to the cam, and a bearing rotatably disposed on the cam pin. The bearing is mechanically coupled to a lifter. The lifter is mechanically coupled to a linear bearing, enabling a smooth reciprocating back-and-forth motion from the rotation of the motor. A top of the cup swells and unswells during an operation cycle of the driver.