【正文】 hich is too plicated in both structure and control. Their reliability and applications in small space(extreme condition environments)and weak signal measurements all bee severe issues. Inertial slider is rather simple, but not very rigid(prone to vibration, thus downgrading the quality of atomic images)and unable to produce enough pushing force. In this paper, we demonstrate a piezoelectric motor that does not have the above limitations. It is implemented by a single piezoelectric scanner tube(PST) that is axially and deeply cut into almost two halves and grips a hollow shaft (HS)inside from both ends by the spring parts of the driving voltages that separately deform the two halves of the PST in one direction and concurrently recover will move the HS one step in the opposite direction, and vice versa. Its pactness, simplicity, rigidity, and large step size make it particularly useful in small space(extreme conditions)and low temperature applications. II. DESIGN AND PRINCIPLE Figure 1 shows the schematic of our design. A photo of the actual setup is given in Fig. 2. Two sapphire rings of thick by and mm inner versus outer diameters are glued(with H74F epoxy from Epoxy Technology)onto the ends of a fourquadrant PST(model of Physik Instrumente, 30 mm long by 10 mm outer diameter by wall thickness with 177。F S=Nbr200 V) and (b) maximum operating voltage (frequency=20 Hz). Although tested in room temperature, the motor has high potential to work in liquid helium temperature for two reasons:(1)its large step size can afford to pay for the thermal contraction still with remarkable step size remaining to produce a move。(b)two kinds of hollow shafts studied. One big advantage of this mutual clamping between the PST and HS at both ends is that this structure is very ?rm(resistant to vibration noise)and can be installed in any direction. Also note that the clamping is elastic(long range forces),implying that large temperature variations will not change the clamping forces signi?cantly and the three maximum static frictions remains equal in value. To operate the motor, two driving voltages D1 and D2 of (a)type are applied to the electrodes E1 and E2 of the PST, respectively(the inner electrode voltage is ?xed at 200 V), which will deform the corresponding semitubular actuators P1 and P2 as follows. P1 and P2 are initialized to expansion states during the ?rst 1/6 period(T1).In T2,P2 shrinks while P1 stays unchanged. This results in a sliding between the free end of P2 and HS rather than a sliding between the base ring and HS, because the P2toHS maximum static friction fr2 is smaller than the sum of the P1toHS and base ringtoHS maximum static frictions, fr1+ frbr(assuming these frictions are much smaller than the blocking forces Fbl1 and Fbl2 of P1 and P2). Next, in T3, P1and P2 both stay in the previous state. This purely “wait”state is a preparation for good synchrony in the next action,which is not necessary and can be dropped to save time. In T4, P1 shrinks while P2 stays unchanged. This induces a sliding between the free end of P1 and HS(y the similar reason to the T2 action).Up to now, both P1 and P2 have changed the states from expansion to contraction without moving the HS with reference to the base ring. T5 is another wait which is again the last 1/6 period(T6),P1 and P2 both expand simultaneously. This time, the sliding happens only between the base ring and HS because frbrfr1+fr2, meaning that P1 and P2 together drag the HS to move one step in the expansion direction from the base ring. Finally, P1 and P2 return to the initial states and the HS has moved one step. This sequence can be repeated to achieve a large travel range. The HS can also move in the oppos