Abstract: A motion producing device in the form of a linear actuator, circular pump, or a robotic or prosthetic limb which functions to produce many kinds of work is provided. The device includes a linear series of alternately spaced fixed and polarity reversible magnets. The fixed and polarity reversible magnets may have more than one magnet assembled as a force unit of magnets of fixed polarity or reversible polarity which is surrounded by a rigid electrically insulating material and that carries rigid electrical conductors in the form of tubes. Between each magnetic force unit is an elastic electrically insulating material allowing expanding or shrinking of the distance between the magnetic force units in accordance with the polarity reversal of the reversible magnetic force units. The elastic expansion or contraction material carries flexible elastic tubes that connect with the rigid tubes to hold a current carrying electrolyte to carry electrical current from a D.C.