A novel ultrasonic levitating bearing excited by three piezoelectric transducers is presented in this work. The transducers are circumferentially equispaced in a housing, with their center lines going through the rotation center of a spindle. This noncontact bearing has the ability to self-align and carry radical and axial loads simultaneously. A finite element model of the bearing is built in ANSYS, and modal analysis and harmonious response analysis are conducted to investigate its characteristics and driving parameters. Based on nonlinear acoustic theory and a thermodynamic theory of ideal gas, the radical and lateral load-carrying models are built to predict the bearing’s carrying capacity. In order to validate the bearing’s levitation force, a test system is established and levitating experiments are conducted. The experimental data match well with the theoretical results. The experiments reveal that the maximum radical and axial levitating loads of the proposed bearing are about 15 N and 6 N, respectively, when the piezoelectric transducers operate at a working frequency of 16.11 kHz and a voltage of 150 V_p-p.

This article proposes a deformable water-mobile robot that can be used for rescue work. The robot body adopts an open-motion chain structure with two degrees of freedom, including two drive modules and one main control module. The three modules are connected through deformation joints, and each drive module is equipped with an underwater thruster. The robot can obtain a triangle, linear shape, curved shape, and U-shape through deformation and have three types of motion: linear shape motion, U-shaped motion, and curved shape motion. In the linear shape, a multi-island genetic algorithm was used to optimize the structural parameters with the minimum resistance and the maximum volume. Floating state analysis was conducted in the U-shape, and the structural parameters were reasonably designed. By experimenting with the robot prototype on water, the robot can achieve oscillating, linear, U-shaped, and horizontal rotary motion, has an automatic adjustment function, and effective buoyancy meets the required requirements.

Soft robots demonstrate an impressive ability to adapt to objects and environments. However, current soft mobile robots often use a single mode of movement. This gives soft robots good locomotion performance in specific environments but poor performance in others. In this paper, we propose a leg–wheel mechanism inspired by bacterial flagella and use it to design a leg–wheel robot. This mechanism employs a tendon-driven continuum structure to replicate the bacterial flagellar filaments, while servo and gear components mimic the action of bacterial flagellar motors. By utilizing twisting and swinging motions of the continuum structure, the robot achieves both wheeled and legged locomotion. The paper provides comprehensive descriptions and detailed kinematic analysis of the mechanism and the robot. To verify the feasibility of the robot, a prototype was implemented, and experiments were performed on legged mode, wheeled mode, and post-overturning motion. The experimental results demonstrate that the robot can achieve legged and wheeled motions. Moreover, it is also demonstrated that the robot still has mobility after overturning. This expands the applicability scenarios of the current soft mobile robot.

The objective of the kinematic model of rock chips is to examine the impact of the driving parameters of drilling tools on the effective chip removal speed, with a view to analyze the chip removal performance of rotary percussion ultrasonic drilling. The discrete element numerical simulation method, EDEM-2022 simulation software, was employed to establish a simulation model, match the simulation parameters, and conduct a simulation study of chip removal under the action of rotary percussion. This was performed to analyze the influence of the driving parameters on the chip conveying process. In order to ascertain the order of parameters affecting the degree of conveyance rate as well as the optimal driving parameters, orthogonal experiments were designed based on Taguchi’s experimental analysis method.

To address the challenges of in-situ lunar water-ice extraction—including limited extraction range, low efficiency, and high energy consumption—this study proposes a thermal drill-based water-ice extraction method utilizing induction heating. Using the Box-Behnken design, response surface methodology, and a multiphysics coupled model, the influences of four key parameters—drill needle diameter, current frequency, coil turn number, and rated input power—are systematically analyzed. The NSGA-II multi-objective optimization algorithm was adopted to obtain the Pareto optimal solution set. This research presents an innovative, parameterized design methodology for the efficient, low-energy extraction of lunar water ice.

This paper presents an ultrasonic sampling penetrator with a staggered-impact mode, which has been developed for the extraction of lunar water ice. A comparison of this penetrator with existing drilling and sampling equipment reveals its effectiveness in minimizing disturbance to the in situ state of lunar water ice. This is due to the interleaved impact penetration sampling method, which preserves the original stratigraphic information of lunar water ice. The ultrasonic sampling penetrator utilizes a single piezoelectric stack to generate the staggered-impact motion required for the sampler. Finite element simulation methods are employed for the structural design, with modal analysis and modal degeneracy carried out. The combined utilization of harmonic response analysis and transient analysis is instrumental in attaining the staggered-impact motion. The design parameters were then used to fabricate a prototype and construct a test platform, and the design’s correctness was verified by the experimental results. In future sampling of lunar water ice at the International Lunar Research Station, the utilization of the ultrasonic sampling penetrator is recommended.