scholarly journals Design and analysis of a new tactile device featuring Magneto-Rheological fluid in control force of robotic surgery

2019 ◽  
Vol 22 (2) ◽  
pp. 264-274
Author(s):  
Phu Xuan Do ◽  
Le Tran Huy Thang
Keyword(s):  
Robotic Surgery ◽  
Tactile Sensor ◽  
Pressure Control ◽  
Tactile Display ◽  
Flow Mode ◽  
Shear Mode ◽  
Control Force ◽  
Haptic Devices ◽  
Deformation Equation ◽  
Magneto Rheological

In this paper, a new artificial skin tissue device which can emulate the stiffness of several organs of human is proposed and analyzed utilizing magneto-rheological (MR) fluid (MR skin). The proposed skin could be applied for the robot-assisted surgery manipulated by haptic devices as a controllable tactile sensor. The method in this paper is design of multi- embedded valve networks inside the structure of the master actuator. These valves use the flow mode and shear mode of MR for pressure control. Deformation equation of the MR skin is derived and the external force contacting the MR skin is also analyzed. After formulation, the proposed tactile display is optimized by using the finite element method software (ANSYS ADPL). It is shown via the optimization that the results can satisfy the initial requirements of the design. From the simulation results, the adjacent coils with similar setup show outstanding results compared with adjacent coils with discordant setup. This directly indicates that the proposed MR skin structure is feasible in the manufacturing and is applicable to haptic devices, especially those used for robotic surgery.

Effect of Internal Pressure on Flow Properties of Magnetorheological Fluids

2011 ◽  
Author(s):  
Andrea Spaggiari ◽  
Eugenio Dragoni
Keyword(s):  
Internal Pressure ◽  
System Design ◽  
Flow Mode ◽  
Shear Mode ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Experimental Apparatus ◽  
Gear Pumps ◽  
Strengthen Effect ◽  
Hydraulic System Design

Magnetorheological (MR) fluids have a lot of applications in the industrial world, but sometimes their properties are not performing enough to meet system requirements. It has been found that in shear mode MR fluids exhibits a pressure dependency called squeeze strengthen effect. Since a lot of MR fluid based devices work in flow mode (i.e. dampers) this paper investigates the behaviour in flow mode under pressure. The system design is articulated in three steps: hydraulic system design, magnetic circuit design and design of experiment. The experimental apparatus is a cylinder in which a translating piston displaces the fluid without the use of standard gear pumps, incompatible with MR fluids. The experimental apparatus measures the MR fluid yield stress as a function of pressure and magnetic field allowing the yield shear stress to be calculated. A statistical analysis of the results shows that the squeeze strengthen effect is present in flow mode as well and the presence of internal pressure is able to enhance the performance of MR fluid by nearly ten times.

BINGHAM AND RESPONSE CHARACTERISTICS OF ER FLUIDS IN SHEAR AND FLOW MODES

2001 ◽  
Vol 15 (06n07) ◽  
pp. 1017-1024 ◽  
Author(s):  
H. G. LEE ◽  
S. B. CHOI ◽  
S. S. HAN ◽  
J. H. KIM ◽  
M. S. SUH
Keyword(s):  
Electric Fields ◽  
Flow Mode ◽  
Shear Mode ◽  
Damping Force ◽  
Response Characteristics ◽  
Operating Modes ◽  
Field Dependent ◽  
Different Temperatures ◽  
Er Damper ◽  
Er Fluid

This paper presents field-dependent Bingham and response characteristics of ER fluid under shear and flow modes. Two different types of electroviscometers are designed and manufactured for the shear mode and flow mode, respectively. An ER fluid consisting of soluble chemical starches (particles) and silicon oil is made and its field-dependent yield stress is experimentally distilled at two different temperatures using the electroviscometers. Time responses of the ER fluid to step electric fields are also evaluated under two operating modes. In addition, a cylindrical ER damper, which is operated under the flow mode, is adopted and its measured damping force is compared with predicted one obtained from Bingham model of the shear and flow mode, respectively.

Face-shear mode ultrasonic tactile sensor array

2012 ◽  
Author(s):  
Kyungrim Kim ◽  
Shujun Zhang ◽  
Jian Tian ◽  
Pengdi Han ◽  
Xiaoning Jiang
Keyword(s):  
Sensor Array ◽  
Tactile Sensor ◽  
Shear Mode ◽  
Tactile Sensor Array

Effect of Pressure on the Flow Properties of Magnetorheological Fluids

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
A. Spaggiari ◽  
E. Dragoni
Keyword(s):  
Flow Mode ◽  
Shear Mode ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Pressure Dependency ◽  
Experimental Apparatus ◽  
Experiment Method ◽  
Gear Pumps ◽  
Strengthen Effect ◽  
System Requirements

Magnetorheological (MR) fluids are widely used in the industrial world; however, sometimes their properties fail to meet system requirements. In shear mode, MR fluids have been found to exhibit a pressure dependency called squeeze strengthen effect. Since a lot of MR fluid based devices work in flow mode (i.e., dampers), this paper investigates the behavior in flow mode under pressure. The system design consists of three steps: the hydraulic system, the magnetic circuit, and the design of experiment method. The experimental apparatus is a cylinder in which a piston displaces the fluid without the use of standard gear pumps, which are incompatible with MR fluids. The experimental apparatus measures the yield stress of the MR fluid as a function of the pressure and magnetic field, thus, enabling the yield shear stress to be calculated. A statistical analysis of the results shows that the squeeze strengthen effect is also present in flow mode, and that the internal pressure enhances the performance of MR fluids by nearly five times.

A novel bi-directional shear mode magneto-rheological elastomer vibration isolator

2020 ◽  
Vol 31 (17) ◽  
pp. 2002-2019 ◽  
Author(s):  
Amir Jalali ◽  
Hashem Dianati ◽  
Mahmood Norouzi ◽  
Hossein Vatandoost ◽  
Mojtaba Ghatee
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Excitation Frequency ◽  
Magnetic Flux Density ◽  
Shear Mode ◽  
Vibration Isolator ◽  
Horizontal Shear ◽  
Shear Modes ◽  
Magneto Rheological ◽  
Mechanical Devices

In this article, a novel bi-directional shear mode magneto-rheological elastomer–based vibration isolator has been designed, fabricated, and characterized to improve the dynamic response and identification of this class of “intellectual” mechanical devices. A heuristic embodiment has been realized in order to design such an isolator wherein both the vertical and horizontal directions can be operated only in the shear mode not only individually but also simultaneously. Two fixtures have been designed for performing the characterization of the magneto-mechanical behavior of the proposed magneto-rheological elastomer isolator in the vertical and horizontal shear modes under wide ranges of strain amplitude (4%–32%), excitation frequency (1–8 Hz), and magnetic flux density (0–220 mT). Experimental results revealed maximum relative magneto-rheological effects of 35% and 27 % in the vertical and horizontal shear modes, respectively. Furthermore, basic mathematical models of single-degree-of-freedom systems, employing the magneto-rheological elastomer–based isolator in the vertical and horizontal shear modes, have been established. The proposed magneto-rheological elastomer isolator in the vertical mode exhibited natural frequency shift of 6.1% by a small increment in the magnetic flux density which approves the potential of the proposed bi-directional shear mode magneto-rheological elastomer–based vibration isolator for vibration control applications, such as seat suspension systems.

A Novel Rotary Magneto-Rheological Damper for Haptic Interfaces

2015 ◽  
Author(s):  
Okan Topcu ◽  
Yigit Tascioglu ◽  
Erhan Ilhan Konukseven
Keyword(s):  
Mr Damper ◽  
Shear Mode ◽  
Haptic Interfaces ◽  
Rotary Valve ◽  
Low Friction ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Fluid Dampers ◽  
Magneto Rheological ◽  
Femm Software

Haptic interfaces require lightweight, small actuators with high force capability and low friction. In this paper, based on the structure of conventional shear mode disc and drum type MR fluid dampers, a lightweight continuous rotary MR damper working in valve mode is designed for haptic interfaces. The proposed design is compared to shear mode disc-type and drum-type designs with similar torque–to–mass ratio via computer simulations. Mathematical models for the resistant torques of both the shear mode and the valve mode are derived. Subsequently, the finite element analysis of electromagnetic circuit calculations was carried out by FEMM software to perform an optimization of the dimensions of the parts such as gap size and thickness. It is shown that the proposed continuous rotary valve mode MR damper is a fine candidate that meets the requirements of haptic interfaces.

Experimental Verification of Controllability of a Mixed Mode MR Fluid Mount

2011 ◽  
Author(s):  
Shuo Wang ◽  
Mohammad Elahinia ◽  
The Nguyen
Keyword(s):  
Mixed Mode ◽  
Alternative Energy ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Hybrid Vehicles ◽  
Flow Mode ◽  
Shear Mode ◽  
Mr Fluid ◽  
Set Up ◽  
Different Levels

With the advent of alternative energy and hybrid vehicles come new vibration problems and challenges that require nontraditional solutions. Semi-active vibration isolation devices are preferred to address the problem due to their effectiveness and affordability. A magnetorheological (MR) fluid mount can provide effective vibration isolation for applications such as hybrid vehicles. The MR fluid can produce different levels of damping when exposed to different levels of magnetic field. The fluid can be working in three modes which are the flow mode, shear mode and squeeze mode. A mixed mode MR fluid mount was designed to operate in a combination of the flow mode and the squeeze mode. Each of the working modes and the combined working mode has been studied. The mount’s performance has been verified in simulation and experiments. Based on the simulation and experimental results, it can be seen that the mount can provide a large range of dynamic stiffness. Given this range of dynamic stiffness, a controller has been designed to achieve certain dynamic stiffness at certain frequencies. The experiments are set up to realize the hardware-in-the-loop tests. Results from the experiments show that the mixed mode MR fluid mount is able to achieve desired dynamic stiffness which is directly related to vibration transmissibility.

Nondimensional Damping Analysis of Flow-Mode Magnetorheological and Electrorheological Dampers

Aerospace ◽  
2003 ◽  
Author(s):  
Wei Hu ◽  
Norman M. Wereley
Keyword(s):  
Magnetic Circuit ◽  
Design Method ◽  
Damping Coefficient ◽  
Flow Mode ◽  
Shear Mode ◽  
Number Range ◽  
Bingham Plastic ◽  
Bingham Number ◽  
Er Damper ◽  
The Relationship

In an effort to develop a Magnetorheological (MR) and Electrorheological (ER) damper initial design method, a quasi-steady relationship between force and velocity exhibited by a flow-mode MR/ER damper is developed based on a Bingham plastic model and a parallel plate assumption. A nondimensional damping coefficient is described as a nonlinear explicit function of an independent nondimensional Bingham number. Since the nondimensional damping coefficient is not a simple analytical function of the Bingham number, a uniform rational approximation approaches is used to determine the relationship between nondimensional damping coefficient and Bingham number. Approximate linear relationship is obtained in a certain Bingham number range. Thus, the quasi-steady flow mode damping approximately consists of a controllable damping and a linear viscous or post-yield damping, which is similar to the behavior of a shear mode damper. The effect on the nondimensional damping coefficient due to the magnetic circuit is also considered by introducing a ration of the length of active region to the total flow gap length.

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