A method to design a magnetorheological damper with large damping force in a limited space is proposed, and a nonlinear model at high velocity is established. First, a magnetorheological damper with radial damping gap is designed and fabricated in this paper. The maximum damping force exceeds 24kN. Secondly, the dynamic characteristics of the designed magnetorheological damper at low velocity and high velocity are tested respectively. The results show that the controllable damping force dominates due to the increase of current at low velocity. When the velocity increases to a certain range, the damping force increases nonlinearly, and the non-controllable damping force is the main component. The damping force calculation model of the magnetorheological damper with radial damping gap at high velocity is obtained. Finally, by comparing the model with the experimental results, the accuracy of the damping force calculation model at high velocity is verified.

Stereolithography apparatus (SLA), a standard 3D printing technology, suffers from post-processing burrs and the use of extra material for support legs. To solve the problem, we propose a novel SLA approach that utilizes a magnetically levitated fluid, enabling the fabrication of desired objects through photocuring and layering processes. The key requirement for the fluid is its good responsiveness to magnetic fields while being curable under specific wavelengths of light. To fulfill the requirement, we developed and evaluated a new magnetic photocurable resin (mPCR) fluid with both magnetic responsiveness and photocurability. Additionally, we designed and implemented a prototype SLA system that incorporates the magnetic levitation technique.

Influence of channel height, magnetic fluid concentration, Reynolds number and magnetic field intensity on heat transfer of magnetic fluid flow in a mini-channel was investigated experimentally. Two mini-channels which has 1 mm and 5 mm of channel height and 1.6 vol% and 3.2 vol% of magnetic fluid are prepared in this study. Reynolds numbers are set to 100, 200 and 300, and magnetic field intensity is varied 100, 300 and 500 mT. The results show that heat transfer is enhanced for 5 mm of channel height by applying strong magnetic field, while heat transfer is slightly suppressed for 1 mm of channel height.

A continuous steel plate production line in steelworks is several kilometers long; over this distance, steel plates suffer from problems such as vibration, friction, distortion, and surface quality degradation, which are caused by contact with rollers. To solve this problem, our research group investigates noncontact guidance control that suppresses the vibration of continuous steel plates by applying an electromagnetic force near the edge of the plates. We analyze and experience the vibration characteristics of steel plates by changing the positions of the electromagnets used in the magnetic guideway for the plates, which are stationary.

In order to control the magnetic field adjusted electrical behaviors in composite piezomagnetic-piezoelectric semiconductor structure, non-uniform piezomagnteic layers are designed. After establishing the mathematical model, the effects of the non-uniform piezomagnetic layers on the electrical field quantities are investigated thoroughly. This work could be the guidance designing magneto-electric devices.

X-ray CT scans were employed to visualize and track the movement of NdFeB particles dispersing permanent magnet urethane elastomer (PMUE) during the compression process. The particle translation and rotation were quantified by analyzing the data obtained from the CT scans. The findings revealed that particles closer to the compression plane exhibited larger translation distances while the amount of rotation remained unaffected by the initial position. Furthermore, it was observed that most particles did not undergo significant rotations beyond 45 degrees.

We have developed a connection system that automatically connects modular robots to each other. For automatic connection, the magnetic flux density was used for connection position estimation using the magnet and the Hall effect IC. The relationship between the relative position and the magnet flux density was identified, and the threshold value was set to determine contact.

In recent years, robot hands using soft materials have been studied. By using a soft material, you can easily grab fragile or various-shaped objects. Many of these soft grippers are pneumatically driven. However, it is required to use an air compressor which is not favorable for agricultural robots or field robots. Therefore, we propose a gripper that uses a magnetically functional fluid for the fingertip and investigated the characteristics. Furthermore, we also employed image processing techniques with the visual sensual camera to extract the contour of objects. This enables us to obtain information such as shapes, centroid, area…which we can use to perform Object detecion using the Raspberry Pi. And in conjunction with the Arduino, we can conduct the automatic grasping for the flexible fingertip robot system.

To realize multi-DOF motions for miniature robots, complex structures and driving mechanisms are usually implemented. This study develops a novel stick-slip robot driven by a single electromagnetic coil, which can accomplish forward, backward, and turning motions. The proposed structure includes four driving legs, a single electromagnetic coil rotatable around the main supporting body, which can switch between two statuses corresponding to linear and rotational modes. By adjusting the coil positions, the driving legs undergo asymmetric deformation. The robot motion is then realized by this system asymmetry, which varies reaction forces at four driving legs during the vibrations caused by the electromagnetic coil. This study proposes a model based on stick-slip frictions to elucidate the operating principles of the developed crawling robot, and examines the structure characteristics and driving capabilities for a 3D-printed prototype.