The manipulators of Scanning Tunneling Microscope (STM) usually use "long-travel" mechanically drived X-Y stages (units) with piezoceramic actuators (travel 25x25 mm, error of positioning delta phi<4 nm along X,Y axes) [1] together with piezoceramic tubes (travel 2x2x1 mic, delta phi<10 nm along X,Y axes and delta phi<0,1 nm along Z axe) [2]. Magnetic- and Electric Rheology (MR and ER) manipulators [3] combine the functions of the both drives in single unit and ensure the precision delta phi<10nm and the length of the travel L less than or equal to 200 mm along X,Y axes and L less than or equal to 400 mic along Z axe. Error of positioning of loop-controlled MR- and ER drive may be expressed [2]: delta phi=delta(r)+delta(db)+delta(f)+delta(i), where delta(r)-"reproduction" error (depends on drive structure and control system and ensures delta(r)=0); delta(db)-"disturbance" error (delta(db)=1...2 nm); delta(f)-error, because of static friction forces action (delta(f)=k(t) . F-st=2I(s)/k(i)=5 nm, where k(t)-transformation coefficient of the drive; F-st-static force in the drive; I-s-"starting" current in drive; k(i)-transformation coefficient of the measuring system); delta(i)-"instrumental" error. In case of a laser interferometer usage (delta(i)=2 nm) the summarised error is delta phi<10 nm. The set of unique parameters of the experimental manipulators is reached by exclusion of traditional valves (with moving elements), also as the elastic elements rigidity increasing, work force of drive increasing and weight of moveable parts shortening.
