scholarly journals Polyharmonic Vibrations of Human Middle Ear Implanted by Means of Nonlinear Coupler

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5121
Author(s):  
Rafal Rusinek ◽  
Joanna Rekas ◽  
Katarzyna Wojtowicz ◽  
Robert Zablotni
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Middle Ear ◽  
Degrees Of Freedom ◽  
Chaotic Vibrations ◽  
Classical Element ◽  
Irregular Motion ◽  
Lumped Masses ◽  
Nonlinear Coupler ◽  
Human Middle Ear

This paper presents a possibility of quasi-periodic and chaotic vibrations in the human middle ear stimulated by an implant, which is fixed to the incus by means of a nonlinear coupler. The coupler represents a classical element made of titanium and shape memory alloy. A five-degrees-of-freedom model of lumped masses is used to represent the implanted middle ear for both normal and pathological ears. The model is engaged to numerically find the influence of the nonlinear coupler on stapes and implant dynamics. As a result, regions of parameters regarding the quasi-periodic, polyharmonic and irregular motion are identified as new contributions in ear bio-mechanics. The nonlinear coupler causes irregular motion, which is undesired for the middle ear. However, the use of the stiff coupler also ensures regular vibrations of the stapes for higher frequencies. As a consequence, the utility of the nonlinear coupler is proven.

scholarly journals Numerical research of biomechanical system with SMA prosthesis

2018 ◽  
Vol 157 ◽  
pp. 02031
Author(s):  
Andrzej Mitura ◽  
Rafal Rusinek
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Middle Ear ◽  
Quality Index ◽  
Multibody System ◽  
Dynamic Responses ◽  
Numerical Research ◽  
Shape Memory Materials ◽  
Human Middle Ear ◽  
Prosthesis Material

In this paper the modelling of special biomechanical mechanism and application of shape memory materials are presented. The model of the human middle ear is made as multibody system. The basic 3dof ear model of the healthy middle ear is modified to represent the damaged ear. A damaged of the ossicular chainis taken into account by adding gap in visco-elastic joints. In addition, an attempt of the ossicles chain reconstruction through prosthesis made of shape memory alloy is presented. Moreover, a new description of the hysteresis sub-loop which characterise prosthesis material is proposed. Finally, dynamic responses of healthy, damaged and reconstructed models of the middle ear are compared by quality index.

scholarly journals Middle ear vibrations with SMA prosthesis. Experimental research

2018 ◽  
Vol 148 ◽  
pp. 12001
Author(s):  
Rafal Rusinek ◽  
Marcin Szymanski ◽  
Grzegorz Teresinski
Keyword(s):  
Transfer Function ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Temporal Bone ◽  
Experimental Research ◽  
Middle Ear ◽  
Round Window ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Middle Ear Prosthesis

The paper focuses on experimental research of a middle ear prosthesis made of shape memory alloy. The prosthesis provides better adjustment to individual patient than classical prosthesis. The shape memory prosthesis is implemented to a fresh temporal bone and vibrations of the round window are recorded by means of the Laser Doppler Vibrometer. Finally, the results are presented in the form of transfer function and compared to the intact and damaged middle ear.

scholarly journals Design of Shape Memory Alloy-Based Soft Wearable Robot for Assisting Wrist Motion

2019 ◽  
Vol 9 (19) ◽  
pp. 4025 ◽  
Author(s):  
Jaeyeon Jeong ◽  
Ibrahim Bin Yasir ◽  
Jungwoo Han ◽  
Cheol Hoon Park ◽  
Soo-Kyung Bok ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Wrist Flexion ◽  
Wearable Robot ◽  
Maximum Torque ◽  
Wrist Motion ◽  
Contraction Ratio ◽  
Flexion Extension ◽  
The Average Range

In this paper, we propose a shape memory alloy (SMA)-based wearable robot that assists the wrist motion for patients who have difficulties in manipulating the lower arm. Since SMA shows high contraction strain when it is designed as a form of coil spring shape, the proposed muscle-like actuator was designed after optimizing the spring parameters. The fabricated actuator shows a maximum force of 10 N and a maximum contraction ratio of 40%. The SMA-based wearable robot, named soft wrist assist (SWA), assists 2 degrees of freedom (DOF) wrist motions. In addition, the robot is totally flexible and weighs 151g for the wearable parts. A maximum torque of 1.32 Nm was measured for wrist flexion, and a torque of larger than 0.5 Nm was measured for the other motions. The robot showed the average range of motion (ROM) with 33.8, 30.4, 15.4, and 21.4 degrees for flexion, extension, ulnar, and radial deviation, respectively. Thanks to the soft feature of the SWA, time cost for wearing the device is shorter than 2 min as was also the case for patients when putting it on by themselves. From the experimental results, the SWA is expected to support wrist motion for diverse activities of daily living (ADL) routinely for patients.

Helical Kirigami-Enabled Centimeter-Scale Worm Robot With Shape-Memory-Alloy Linear Actuators

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Geometrical Parameters ◽  
Parallel Structures ◽  
Complete Procedure ◽  
Motion Characteristics

The wormlike robots are capable of imitating amazing locomotion of slim creatures. This paper presents a novel centimeter-scale worm robot inspired by a kirigami parallel structure with helical motion. The motion characteristics of the kirigami structure are unravelled by analyzing the equivalent kinematic model in terms of screw theory. This reveals that the kirigami parallel structure with three degrees-of-freedom (DOF) motion is capable of implementing both peristalsis and inchworm-type motion. In light of the revealed motion characteristics, a segmented worm robot which is able to imitate contracting motion, bending motion of omega shape and twisting motion in nature is proposed by integrating kirigami parallel structures successively. Following the kinematic and static characteristics of the kirigami structure, actuation models are explored by employing the linear shape-memory-alloy (SMA) coil springs and the complete procedure for determining the geometrical parameters of the SMA coil springs. Actuation phases for the actuation model with two SMA springs are enumerated and with four SMA springs are calculated based on the Burnside's lemma. In this paper, a prototype of the worm robot with three segments is presented together with a paper-made body structure and integrated SMA coil springs. This centimeter-scale prototype of the worm robot is lightweight and can be used in confined environments for detection and inspection. The study presents an interesting approach of integrating SMA actuators in kirigami-enabled parallel structures for the development of compliant and miniaturized robots.

Development of a Proof-of-Concept Aircraft Smart Control System

2009 ◽  
Author(s):  
Parsaoran Hutapea
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Flight Control ◽  
Degrees Of Freedom ◽  
Cooling System ◽  
Control Mechanisms ◽  
Proof Of Concept ◽  
Concept Model ◽  
Actuation System ◽  
Smart Control

Hutapea et al (Aircraft Engineering and Aerospace Technology: 80(4), 439–444, 2008) proposed an actuation system based on shape memory alloy springs for a wing flap of an aircraft. A continued research and development of these previously demonstrated smart flight control mechanisms was performed with the goal to develop a proof-of-concept shape memory alloy (SMA) actuation system, which utilizes SMA springs to control the six degrees of freedom of an aircraft. As a significant advancement to the overall actuation system, an air burst-cooling system was added to increase the cooling rate of the SMA springs by means of forced convection. A one-sixth scale proof-of-concept model was constructed to demonstrate and to verify the final actuation system design.

Analysis of Shape Memory Alloy Components Using Beam, Shell, and Continuum Finite Elements

2010 ◽  
Author(s):  
Darren Hartl ◽  
Tyler Zimmerman ◽  
Matthew Dilligan ◽  
James Mabe ◽  
Frederick Calkins
Keyword(s):  
Finite Elements ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Analysis Tool ◽  
Three Dimensional Model ◽  
Restoring Force ◽  
Element Analysis

This work discusses the increased capabilities of a three-dimensional analysis tool for shape memory alloy engineering components. As the number and complexity of proposed SMA applications increases, engineers and designers must seek out or develop more capable predictive methods. Three-dimensional models implemented in a continuum finite element analysis (FEA) framework can be applied to most SMA component geometries. However, such methods may require fine meshes in 3-D space, resulting in many degrees of freedom and potentially long analysis times. On the other hand, constitutive models implemented in one dimension can be simple and fast, but are restricted to a limited class of problems for which such reductions are appropriate (e.g., rods and beams). More recently, engineers have begun investigating more complex SMA bending components for which 2-D shell elements might provide a computationally efficient FEA discretization. Here we consider a single modeling tool (a material subroutine) that combines 1-D, 2-D, and 3-D implementations for use in a general FEA framework. As an example analysis case, we consider an SMA bending element that has been adhesively bonded to a carbon fiber-reinforced polymer (CFRP) laminate and is subjected to thermally-induced actuation. The active SMA and passive composite components are bonded in a pre-stressed configuration such that the elastic laminate provides a variable restoring force to the SMA during transformation, resulting in repeatable actuation cycles. This two-part bonded configuration is analyzed using different types of finite elements (1-D beam, 2-D shell, and full 3-D continuum elements). The constitutive behavior of the shape memory alloy is defined using an established three-dimensional model based on continuum thermodynamics and motivated by the methods of classical plasticity. A user material subroutine (UMAT) in an Abaqus Unified FEA framework is used to implement the model. The methodology for capturing 1-D, 2-D, and 3-D thermomechanical response in a single such UMAT is described. The run times of the various analyses are compared, and the relative accuracies of the results are discussed.

SMA-Net: A Deformable Morphology Robot Using Shape Memory Alloy

2002 ◽  
Vol 14 (3) ◽  
pp. 290-297 ◽  
Author(s):  
Takashi Nagai ◽  
◽  
Hiroshi Yokoi ◽  
Yukinori Kakazu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Design Research ◽  
Control Method ◽  
Lattice Structure ◽  
Physical Property ◽  
Developmental Study ◽  
Passive Deformation ◽  
Robotics Design

Deformation of morphology is one goal of advanced robotics design research. This study started from a project of the development of a morph-functional machine, where the developmental study of a deformable robot which can behave like an ameba, is one of the main topics. This paper proposes the prototype design of a deformable morphology robot based on the lattice structure of elastic elements, shape memory alloy springs. The proposed structure of SMA-Net has both passively deformable functionality and active deformability. The functions of deformability of SMA-Net give new concepts of robotics design. However, it becomes difficult to control overall behavior because of the large degrees of freedom of the structure, external force comes into passive deformation and it makes change of physical property of motion control, and the relation between elements of robot yield nonlinear dynamics. Therefore, as first step for control, we investigated the movement mechanism of the robot. The proposed control method is periodic ON/OFF control, system parameters of SMA-Net are explored to find the resonance phase of the whole structure. Experiments show basic deformations of SMA-Net and the motion of translation and rotation.

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