Magnetorheological Materials and Application Systems

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "E:Engineering and Technology".

Deadline for manuscript submissions: 31 August 2024 | Viewed by 2372

Special Issue Editors


E-Mail Website
Guest Editor
College of Opto-Electronic Engineering , Chongqing University, Chongqing, China, 400044
Interests: magnetorheological materials, devices, and systems; noise and vibration active control; the ultra-precision machining and testing

Special Issue Information

Dear Colleagues,

Despite numerous works on magnetorheological materials (fluids, elastomers, greases, gels, and foams) since the 1990s, few application systems have been commercialized, for example, automotive shock absorbers. One of the potential solutions to develop successful market products utilizing MR materials is resolving the temperature problem that affects the field-dependent properties of such materials and application systems. Recently, studies on this topic have actively sought to mitigate adverse temperature-related effects by proposing recipes such as the addition of nanosized particles and proper additives. However, most of the methods proposed so far have a limitation or trade-off as a result. For example, the thermal conductivity of MR materials can be reduced, but the field-dependent yield stress is decreased.

Based on the topic "Magnetorheological Materials and Application Systems", we aim to collect articles for a Special Issue in the journal Micromachines. We hope to accelerate the technology of MR materials in several research fields, including chemical engineering, chemistry, polymer sciences, chemical physics, mechanical engineering, electrical engineering, and medical engineering.

We look forward to receiving your contributions.

Prof. Dr. Seung-Bok Choi
Prof. Dr. Miao Yu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • magnetorheological materials
  • temperature effect
  • thermal conductivity
  • heat transfer

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

15 pages, 13175 KiB  
Article
Design and Control of Upper Limb Rehabilitation Training Robot Based on a Magnetorheological Joint Damper
by Jintao Zhu, Hongsheng Hu, Wei Zhao, Jiabin Yang and Qing Ouyang
Micromachines 2024, 15(3), 301; https://doi.org/10.3390/mi15030301 - 22 Feb 2024
Viewed by 604
Abstract
In recent years, rehabilitation robots have been developed and used in rehabilitation training for patients with hemiplegia. In this paper, a rehabilitation training robot with variable damping is designed to train patients with hemiplegia to recover upper limb function. Firstly, a magnetorheological joint [...] Read more.
In recent years, rehabilitation robots have been developed and used in rehabilitation training for patients with hemiplegia. In this paper, a rehabilitation training robot with variable damping is designed to train patients with hemiplegia to recover upper limb function. Firstly, a magnetorheological joint damper (MR joint damper) is designed for the rehabilitation training robot, and its structural design and dynamic model are tested theoretically and experimentally. Secondly, the rehabilitation robot is simplified into a spring-damping system, and the rehabilitation training controller for human movement is designed. The rehabilitation robot dynamically adjusts the excitation current according to the feedback speed and human–machine interaction torque, so that the rehabilitation robot always outputs a stable torque. The magnetorheological joint damper acts as a clutch to transmit torque safely and stably to the robot joint. Finally, the upper limb rehabilitation device is tested. The expected torque is set to 20 N, and the average value of the output expected torque during operation is 20.02 N, and the standard deviation is 0.635 N. The output torque has good stability. A fast (0.5 s) response can be achieved in response to a sudden motor speed change, and the average expected output torque is 20.38 N and the standard deviation is 0.645 N, which can still maintain the stability of the output torque. Full article
(This article belongs to the Special Issue Magnetorheological Materials and Application Systems)
Show Figures

Figure 1

15 pages, 8672 KiB  
Article
Effect of Additives on Tribological Performance of Magnetorheological Fluids
by Songran Zhuang, Yongbing Cao, Wanli Song, Peng Zhang and Seung-Bok Choi
Micromachines 2024, 15(2), 270; https://doi.org/10.3390/mi15020270 - 14 Feb 2024
Viewed by 636
Abstract
In this study, nano-diamond (ND) and MoS2 powder are used as additives in a carbonyl iron-based magnetorheological fluid (MRF) to improve its tribological performance. MRFs are prepared by dispersing 35 wt.% of CI particles in silicone oil and adding different proportions (0, [...] Read more.
In this study, nano-diamond (ND) and MoS2 powder are used as additives in a carbonyl iron-based magnetorheological fluid (MRF) to improve its tribological performance. MRFs are prepared by dispersing 35 wt.% of CI particles in silicone oil and adding different proportions (0, 1, 3, or 5 wt.%) of ND and MoS2 additives. Seven kinds of MRFs are made and tested using reciprocating friction and wear tester under different normal loads, and then the friction characteristics are evaluated by analyzing the experimental results. The morphological properties of MRFs and contacting surfaces before and after the tests are also observed using a scanning electron microscope and analyzed via energy-dispersive X-ray spectroscopy. The results show that the appropriate weight percentage of MoS2 additives may decrease the friction coefficient and wear zone. It is also demonstrated from detailed analyses of worn surfaces that the wear mechanism is influenced not only by additives, but also by the applied normal load and magnetic field strength. Full article
(This article belongs to the Special Issue Magnetorheological Materials and Application Systems)
Show Figures

Figure 1

19 pages, 16452 KiB  
Article
Experimental Study on the Skyhook Control of a Magnetorheological Torsional Vibration Damper
by Zhicheng Wang, Hongsheng Hu, Jiabin Yang, Jiajia Zheng, Wei Zhao and Qing Ouyang
Micromachines 2024, 15(2), 236; https://doi.org/10.3390/mi15020236 - 02 Feb 2024
Viewed by 768
Abstract
This study proposes a dual-coil magnetorheological torsional vibration damper (MRTVD) and verifies the effectiveness of semi-active damping control to suppress the shaft system’s torsional vibration via experimental research. Firstly, the mechanical model of the designed MRTVD and its coupling mechanical model with the [...] Read more.
This study proposes a dual-coil magnetorheological torsional vibration damper (MRTVD) and verifies the effectiveness of semi-active damping control to suppress the shaft system’s torsional vibration via experimental research. Firstly, the mechanical model of the designed MRTVD and its coupling mechanical model with the rotating shaft system are established. Secondly, the torsional response of the shaft system is obtained via resonance experiments, and the influence of the current on the torsional characteristics of the magnetorheological torsional damper is analyzed. Finally, the MRTVD is controlled using the skyhook control approach. The experimental results demonstrate that when the main shaft passes through the critical speed range at various accelerations, the amplitude of the shaft’s torsional vibration decreases by more than 15%, and the amplitude of the shaft’s torsional angular acceleration decreases by more than 22%. These conclusions validate the inhibitory effect of MRTVD on the main shaft’s torsional vibrations under skyhook control. Full article
(This article belongs to the Special Issue Magnetorheological Materials and Application Systems)
Show Figures

Figure 1

Back to TopTop