The present invention provides a unit or segment having a ball, a socket and a connector with the connector physically linking the ball and socket together such that a main opening of the socket continuous with the socket cavity faces away from the connected ball. Alternatively, a unit/segment may instead include a ball and a socket coupled directly together. Elongated structures comprising a plurality of units joined together in series, such as through ball joints and other connections, are further provided that may vary greatly in length and size. The ball and socket may have corresponding electromagnets and magnetic materials, respectively, that may attract or repel each other to cause controlled rotational movement of the individual ball joint(s) by controlling the operation of the electromagnets. Higher order structures including one or more elongated structures are further provided. Methods for constructing and/or operating units and/or elongated structures are further provided.