scholarly journals Scissors-Type Haptic Device Using Magnetorheological Fluid Containing Iron Nanoparticles

Technologies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 26 ◽  
Author(s):  
Mioto Waga ◽  
Yuuki Aita ◽  
Junichi Noma ◽  
Takehito Kikuchi ◽  
Yoshimune Nonomura

The mechanical ability and usefulness of simulation systems can be improved by combining a tactile display with a remote control or medical simulation systems. In this study, a scissors-type haptic device containing magnetorheological fluid (MR fluid) in its fulcrum is developed. We evaluate the mechanical response to the applied voltage and realize the presence of mechanical stimuli when a subject grasps or cuts the corresponding objects. When the magnetic field around the MR fluid is controlled by an electric voltage of 150–500 mV, the torque linearly increases from 0.007 ± 0.000 to 0.016 ± 0.000 N m. The device can provide tactile stimuli with 0.1 s of resolution. We also determined the voltage profiles based on typical force profiles obtained during grasping/cutting processes and evaluated the torque using a mechanical evaluation system. Features of the force profiles related to the soft and sticky feels were reconstructed well.

Technologies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 66 ◽  
Author(s):  
Mioto Waga ◽  
Yuuki Aita ◽  
Junichi Noma ◽  
Yoshimune Nonomura

Understanding the dynamic phenomena in grasping/cutting processes with scissors is important for the design of surgical robots and virtual reality systems. Here, we show the relationship between the mechanical stimuli and tactile sensations when forceps or scissors are used. Nineteen subjects grasped or cut objects and evaluated the tactile sensations in each of the processes. To conduct the tactile and mechanical evaluation simultaneously, subjects operated scissors that were fixed to a mechanical evaluation system. When subjects grasped urethane resin, stainless steel plate, and adhesive tape, soft, hard, and sticky feels were perceived, respectively. Dry, hard, and creaking feels were perceived in the paper cutting process. In addition, we observed four characteristic tangential force profiles in the processes. Regression analysis suggests the following findings: Hardness is perceived by the change of force and blade movement when the scissors make contact with the object. Stickiness is caused by the increase and decrease of force at the moment of peeling when the scissors break contact with the object. The cutting sensation is affected by fine force fluctuations during the scissors closing and the rapidly decreased force at the moment of cutting completion.


Author(s):  
Y K Ahn ◽  
J-Y Ha ◽  
Y-H Kim ◽  
B-S Yang ◽  
M Ahmadian ◽  
...  

This paper presents an analytical and experimental analysis of the characteristics of a squeeze-type magnetorheological (MR) mount which can be used for various vibration isolation areas. The concept of the squeeze-type mount and details of the design of a squeeze-type MR mount are discussed. These are followed by a detailed description of the test set-up for evaluating the dynamic behaviour of the mount. A series of tests was conducted on the prototype mount built for this study, in order to characterize the changes occurring as a result of changing electrical current to the mount. The results of this study show that increasing electrical current to the mount, which increases the yield stress of the MR fluid, will result in an increase in both stiffness and damping of the mount. The results also show that the mount hysteresis increases with increase in current to the MR fluid, causing changes in stiffness and damping at different input frequencies.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Jin Huang ◽  
Ping Wang ◽  
Guochao Wang

Magnetorheological (MR) disk-type isolating dampers are the semi-active control devices that use MR fluids to produce controllable squeezing force. In this paper, the analytical endeavor into the fluid dynamic modeling of an MR isolating damper is reported. The velocity and pressure distribution of an MR fluid operating in an axisymmetric squeeze model are analytically solved using a biviscosity constitutive model. Analytical solutions for the flow behavior of MR fluid flowing through the parallel channel are obtained. The equation for the squeezing force is derived to provide the theoretical foundation for the design of the isolating damper. The result shows that with the increase of the applied magnetic field strength, the squeezing force is increased.


2021 ◽  
pp. 1-24
Author(s):  
Manish Kumar Thakur ◽  
Chiranjit Sarkar

Abstract In this research work, graphite flake has been used as an additive in magnetorheological (MR) fluid to improve its thermal and tribological performance. MR fluids with varying amounts of graphite flakes (0.5, 1, 2, 3, 4, and 5 wt%) are prepared to show effective thermal and tribological performance. A test rig is developed with a DC motor, torque sensor, and MR clutch operated in a shear mode to test the torque transmission. Results show the lubrication effects of graphite flakes in MR fluid. Torque transmission is improved in on-state and off-state using graphite flakes based MR fluid as compared to conventional MR fluid. Heating of MR clutch is also reduced with the graphite flakes based MR fluid. Wear marks and damages are decreased significantly with the increased amount of graphite flakes as found in surface roughness tests. SEM and EDS are used to characterize the worn surfaces. This research provides information about the effectiveness of graphite flakes in the MR clutch to improve the device's performance.


2012 ◽  
Vol 23 (9) ◽  
pp. 969-978 ◽  
Author(s):  
Murat Ocalan ◽  
Gareth H. McKinley

The interaction between magnetorheological (MR) fluid particles and the walls of the device that retain the field-responsive fluid is critical as this interaction provides the means for coupling the physical device to the field-controllable properties of the fluid. This interaction is often enhanced in actuators by the use of ferromagnetic walls that generate an attractive force on the particles in the field-on state. In this article, the aggregation dynamics of MR fluid particles and the evolution of the microstructure in pressure-driven flow through ferromagnetic channels are studied using custom-fabricated microfluidic devices with ferromagnetic sidewalls. The aggregation of the particles and the time-dependent evolution in the microstructure is studied in rectilinear, expansion and contraction channel geometries. These observations help identify methods for improving MR actuator design and performance.


2019 ◽  
Vol 374 (1779) ◽  
pp. 20180221 ◽  
Author(s):  
Anabel-Lise Le Roux ◽  
Xarxa Quiroga ◽  
Nikhil Walani ◽  
Marino Arroyo ◽  
Pere Roca-Cusachs

Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue ‘Forces in cancer: interdisciplinary approaches in tumour mechanobiology’.


2016 ◽  
Vol 66 (4) ◽  
pp. 374
Author(s):  
Reji John ◽  
Shiv Kumar

An intelligent semi-active anti-vibration mount using a magnetorheological (MR) fluid is designed and developed for onboard applications. The mount consists of a load bearing elastomer, MR fluid chamber; MEMS based vibration sensor and a controller for closed loop feedback mechanism. The controller regulates the solenoid current in the MR fluid chamber, which in turn regulates the flow of MR fluid through the valve. Comparison of the performance of MR mount with a passive resilient rubber mount shows that the former provides 7 dB extra damping at resonance compared to the later and the isolation of MR mount starts at 10 Hz compared to 50 Hz by rubber mount. This mount can operate in real time, passive and active modes by using a closed loop feedback control mechanism. The efficacy of the mount for outdoor applications is evaluated by characterizing the mechanical, environmental, electrical and electromagnetic properties as per MIL-17185, JSS-55555 and IEC 61000 standards and found to be superior compared to passive mounts. The mount is being evaluated for onboard applications in INS Ranvijay.


Sign in / Sign up

Export Citation Format

Share Document