Insertion into delicate tissue, such as retina vein occlusion, cell manipulation, and vitreoretinal injection, poses challenges to surgeons and biomedical researchers due to the high resolution, large movement range, compact structure, and multi-DOF output requirements. In order to meet these requirements, a 2-DOF arched needle insertion device driven by inertial piezoelectric actuator was proposed in this article. This device could perform theoretical unlimited translational movement and full rotation with high step resolution. A prototype was fabricated with compact structure, the length and diameter were 230 and 32 mm, respectively. The experimental tests were carried out, the insertion device output 2.47 μ m and 0.56 mrad step distance with maximum velocity of 382 μ m/s and 200.9 mrad/s under 120 V driving signals, the maximum insertion force of 32 mN was measured. Additionally, a handheld controller with friendly user interface was also developed for open-loop control utilization, which could automatically calculate and generate the required control signals according to the motion command. This device explores the biomedical application of inertial piezoelectric actuator within a compact size, providing a new choice for numerous innovative treatment and biological research involving precision operation.

Micro/nano manipulators using piezoelectric actuators are extensively applied in precision manipulation fields. In this article, a novel 2-DOF micro/nano manipulator with compact structure is proposed, designed, fabricated, and tested. Different movers can be actuated by only single miniature piezoelectric tube actuator (PTA) to achieve multimotion forms, including 2-DOF linear–linear motion, linear–rotary motion, and rotary–rotary motion in two orthogonal directions. Above all, the configuration and operating principle are amply depicted. Then, the theoretical analyses are accomplished to design the PTA, and the finite-element method is undertaken to validate the theoretical modeling. Ultimately, a prototype of the manipulator is manufactured and experimentally investigated for its output performances. The test results indicate that the developed manipulator can achieve the maximum rotary speed of 0.171 rad/s around the X -axis and 0.169 rad/s around the Y -axis. Furthermore, the angular displacement resolutions are measured to be 0.54 and 0.57 μ rad around X - and Y -axis, respectively. All the results state that the developed micro/nano manipulator not only has distinct multimotion outputs, but also possess superior characteristics in terms of both motion range and displacement resolution, which is expected to be applied into precise positioning and microassembly.

Problems of large sizes and low displacement resolutions widely exist in most of the pole-climbing robots based on electromagnetic or electrostatic motors, which greatly decrease the reachable workspace and influence their utility for inspection tasks. Here, we present a piezoelectric pole-climbing robot (Crabbot) to overcome these shortcomings, which has the advantages of small size, high load-to-weight ratio and high resolution. Moreover, Crabbot can climb poles with different cross-sections through the designed crab-like clamp. This robot was composed of two clamping units and an elongation unit, and the stepping displacements were amplified by the designed flextensional mechanism. A prototype with weight of 0.35 kg was manufactured, the external dimension was 50 × 54 × 86 mm. Experimental results showed that the robot achieved a maximum speed of 100.9 μ m/s under a voltage of 150 V and a frequency of 9 Hz; moreover, a load weight ratio of 1.42 and a displacement resolution of 85 nm were obtained. As a demonstration of its potential for industrial applications, Crabbot achieved stable step motion on climbing poles of different cross-sections under different climbing angles.

Inchworm rotary piezoelectric actuators (PAs) have been widely utilized in the ultraprecision rotary positioning mechanisms because of their high precision and theoretical no backward motions. Existing inchworm rotary PAs are still bothered with the complicated structures driven by at least three piezoelectric stacks (PSAs) and relatively low speed. In this article, inspired by the finger structure, we present a simplified inchworm rotary PA driven by only two PSAs. The human finger twist motion is first imitated and utilized to increase the rotation from one to four times in one cycle, which improves the output speed and no backward motion can be observed in the rotation curves. Under a voltage of 150 V and a frequency of 20 Hz, the actuator achieved a maximum rotation speed of 0.16 rad/s, a carrying load of 0.5 kg and an output torque of 0.05 N·m. Furthermore, this actuator achieved a high step repeatability in the large scale of 360°, whose maximum deviation is less than 0.8 mrad.

It is difficult to obtain linear output displacements for stepping piezoelectric platform due to their discontinuous outputs. Inspired by the theory that the maximum static friction force is greater than the sliding friction force, in this letter, we propose a bipedal alternating inertial actuation mode (BAIAM) to improve the displacement linearity of the stepping platform. The output displacements are measured, the linear fitting is carried out by the least square method, the correlation coefficient and linear fitting function are used to evaluate the displacement linearity, and the correlation coefficients of the forward and backward motions are calculated as 0.9998 and 0.9999 in BAIAM, respectively, which verifies the effectiveness of the proposed method. The closed-loop experiments in BAIAM are also carried out, and the steady-state errors for the target position of ±40 μ m within ±0.2 μ m in the point-to-point positioning control experiments are achieved. The experimental results confirm that the developed platform can be applied to precision fields requiring a large travel range, planar two-degree-of-freedom motion, and linear outputs.