Investigation of a shape memory alloy releasable mechanism applied in space environment

2020 ◽  
Vol 64 (1-4) ◽  
pp. 393-401
Author(s):  
Kan Bian ◽  
Chunhua Zhou ◽  
Fagang Zhao ◽  
Yipeng Wu ◽  
Ke Xiong
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Response Speed ◽  
Space Environment ◽  
Maintenance Cost ◽  
Heating Efficiency ◽  
Output Force ◽  
Maximal Output ◽  
New Type ◽  
Sma Spring

Though the conventional pyrotechnic fastener mechanisms are widely used in spacecraft for their reliable releasable-fastening function, they still have several unavoidable problems: physical shock, high maintenance cost, to name a few. This paper introduces a new type of smart releasable mechanism based on a Shape Memory Alloy (SMA) spring and its corresponding heating apparatus. To obtain the high heating efficiency and increase the response speed, the SMA spring is transitionally fit with the heating apparatus shell instead of directly heating by electric current. As soon as the heating apparatus begins to work, the SMA spring will provide an un-locking force to release the fastening device within the standard time, which also realizes the similar releasable-fastening function comparing with the conventional pyrotechnic fastener mechanisms. In order to ensure the reliability of space products, the heating apparatus is composed of two identical ceramic heating elements which can be controlled independently or synchronously. Finally, the experimental results clearly show that, under the satellite power supply at the constant value of 28 V, the SMA spring can reach the desired 30 N unlocking force within 93 s and 51 s by single or dual heating elements, respectively. The maximal output force can even be increased as large as 40 N under the limited volume of the releasable mechanism.

Research on novel shape memory alloy multi-fingered humanoid hand

2007 ◽  
Vol 221 (9) ◽  
pp. 1131-1140 ◽  
Author(s):  
K Yang ◽  
C L Gu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Parameters ◽  
Human Beings ◽  
Statistical Research ◽  
Offset Distance ◽  
Maximum Angle ◽  
Output Force ◽  
New Type ◽  
Humanoid Hand

Two new type actuators named planar bending embedded shape memory alloy actuator (ESMAA) and spacial bending ESMAA were presented. Using shape memory effect of SMA wires and elasticity of room temperature vulcanization silicone rubber, the ESMAAs could output force and bend displacement steadily. Furthermore, a novel three-fingered humanoid robot hand consisting of six ESMAAs was developed first. The structural parameters of the actuators, such as rod's radius, wire's radius, wire's recoverable curvature, and offset distance were optimized by combining analytical model with experimental results. On the basis of bionics, the lengths of hand's knuckles were determined through statistical research on the configuration of human beings' hands. The locations of fingers were carefully chosen through a volume optimal index. It is shown in the experiments that maximum angle between ends' tangents of each finger are 68.5°, 79°, and 79°, respectively. The tip of each finger could reach its final position approximately at the same time and by controlling the bending of each finger, the hand could accomplish fine manipulation like that of a human being.

Research and application of novel planar bending embedded shape memory alloy actuator

2007 ◽  
Vol 221 (2) ◽  
pp. 249-257 ◽  
Author(s):  
K Yang ◽  
C L Gu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Structural Parameters ◽  
Hysteresis Loops ◽  
Response Speed ◽  
Experimental Results ◽  
Elastic Rod ◽  
Control Precision ◽  
New Type

To overcome low-response speed and low-control precision in the existing traditional shape memory alloy (SMA) actuators, a new type of structure named planar bending embedded SMA actuator was developed. Two SMA wires were embedded in parallel with the axis of the elastic rod. The recovering wire, which was superposed along rod's axis, was set to obtain ‘U’ memory shape and the restoring wire, which was placed off-axially, got straight memory shape. The differential stain gauges were located at suitable position in corresponding to the actuator's bending direction in order to measure the signal of displacement. By making use of continuity, common origin and common limit conditions, and adjusting martensite fraction coefficients appropriately, the analytical model was deduced to adequately account for the presence of major and minor hysteresis loops. The structural parameters of 60 mm long actuator, such as rod's radius, wire's radius, wire's recoverable curvature, and offset distance, were optimized by combining analytical model with experimental results. The experimental results prove the merits in optimal prototype.

scholarly journals Shape Memory Alloy(SMA) Actuated Microfluidic Colour-Changing System

2020 ◽  
Vol 38 (2) ◽  
pp. 377-383
Author(s):  
Min Zhang ◽  
Songjing Li
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
High Reliability ◽  
Response Speed ◽  
Fast Response ◽  
Microfluidic System ◽  
Present System ◽  
Experimental Conditions ◽  
Output Displacement ◽  
Sma Spring

In order to improve the performances of microfluidic actuators, a microfluidic actuating way based on the shape memory alloy(SMA) is presented, which is applied for the liquids circulation of a microfluidic colour-changing system. A SMA spring is used as the main actuating part, a microfluidic actuating device based on the SMA spring is designed and fabricated. The models for the SMA spring and the whole SMA actuated microfluidic system are established, the experimental platform is built. The temperature properties, output displacement performances and pressure responses of the present system are simulated and tested under different experimental conditions. Comparing with traditional microfluidic actuating systems, the SMA actuated microfluidic colour-changing system is driven by using DC power, small in size, convenient in operation, and has fast response speed and high reliability.

scholarly journals Development of Subcarangiform Bionic Robotic Fish Propelled by Shape Memory Alloy Actuators

2021 ◽  
Vol 71 (1) ◽  
pp. 94-101
Author(s):  
M. Muralidharan ◽  
I.A. Palani
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Open Loop ◽  
Robotic Fish ◽  
Water Medium ◽  
Light Weight ◽  
Caudal Fin ◽  
Locomotion Pattern ◽  
Sma Spring

In this paper, a shape memory alloy (SMA) actuated subcarangiform robotic fish has been demonstrated using a spring based propulsion mechanism. The bionic robotic fish developed using SMA spring actuators and light weight 3D printed components can be employed for under water applications. The proposed SMA spring-based design without conventional motor and other rotary actuators was able to achieve two-way shape memory effect and has reproduced the subcarangiform locomotion pattern. The positional kinematic model has been developed and the dynamics of the proposed mechanism were analysed and simulated using Automated Dynamic Analysis of Mechanical Systems (ADAMS). An open loop Arduino-relay based switching control has been adopted to control the periodic actuation of the SMA spring mechanism. The undulation of caudal fin in air and water medium has been analysed. The caudal fin and posterior body of the developed fish prototype have taken part in undulation resembling subcarangiform locomotion pattern and steady swimming was achieved in water with a forward velocity of 24.5 mm/s. The proposed design is scalable, light weight and cost effective which may be suitable for underwater surveillance application.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

Design, Simulation and Testing of Shape Memory Alloy Actuator for Mixing Two Solutions in High-Pressure Optical Cell for Biophysical Studies

2006 ◽  
Author(s):  
Hongchun Xie ◽  
Jack Zhou ◽  
Parkson Chong
Keyword(s):  
High Pressure ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nickel Titanium ◽  
Intensity Change ◽  
Optical Cell ◽  
Pull Out ◽  
Spring Force ◽  
Heat Response ◽  
Sma Spring

Window-type high-pressure optical cells (HPOC) such as the one designed by Paladini and Weber [Rev. Sci. Instrum. 52, (1981) p. 419] have provided biophysicists a powerful tool to understand the structure-function relationships of biological molecules. However, the conventional HPOC is only good for single solution testing and does not allow for quick mixing and stirring of additional components while the sample is under pressure. To mix two solutions under pressure, Zhou et al [Rev. Sci. Instrum. 69, (1998) p. 3958] developed a laser activated dual chamber HPOC. However, the expensive laser device and its unavailability in most laboratories make the application difficult. In a later study, Zhou et al. [Rev. Sci. Instrum. 71, (2000) p. 4249] introduced shape memory alloy (SMA) as an actuator to unplug a urethane stopper with a biasing spring for agitation. The drawback is that the biasing spring blocks the observing light beam and creates unwanted reflections. This research is to construct an actuator with concentric SMA spring and compressive biasing spring: an SMA helical tensile spring to pull out the stopper to let two solutions mix; and a helical compressive spring to bias and to agitate solutions, and to leave the lower half cuvette clear for optical observation. Due to the limited space in the cuvette, the alignment of two springs is critical for both motion and heat response to activate each spring separately. This paper discusses the design of SMA actuator, SMA spring testing and mixing testing by the SMA spring actuator. Since SMA (nickel-titanium) spring is not solderable and crimping method is limited due to the space, a conductive adhesive is used not only to fix the alignment between springs and cap, but also to conduct electric current. Spring force testing was done by INSTRON. Mixing testing used flourescein intensity change to trace the mixing process. The bio-compatibility of the nickel-titanium SMA with proteins and phospholipids has also been tested.

Research on Walking Mechanism Base on Biological Metal Fibre

2013 ◽  
Vol 785-786 ◽  
pp. 1267-1272
Author(s):  
Shi Ju E ◽  
Xuan Zhong Ding
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Trajectory Planning ◽  
New Type ◽  
Simulation Results ◽  
Metal Fibre ◽  
Walking Mechanism

A new walking mechanism base on biological metal fibre is study in the paper. It used a new type of shape memory alloy (biological metal fibre, BMF) as actuator. The multilegged walking mechanism is employ and study. Its mobile mechanism and trajectory planning is analysed so as to achieve miniaturization goals. The simulation results showed that the multilegged walking mechanism could be effectively driven by the actuator base on BMF.

Thermo-Mechanical Modeling of a Shape Memory Alloy Heat Engine

2011 ◽  
Author(s):  
Christopher B. Churchill ◽  
John Shaw
Keyword(s):  
Heat Transfer ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Heat Engine ◽  
The United States ◽  
Thermodynamic Efficiency ◽  
Low Grade ◽  
Heat Engines ◽  
Deformation Mechanics ◽  
Sma Spring

Two thirds of the energy generated in the United States is currently lost as waste heat, representing a potentially vast source of green energy. Low Carnot efficiency is an inherent limitation of extracting energy from low-grade thermal sources (temperature gradients near or below 100C), and SMA heat engines could be useful for those applications where low weight and packaging are overriding considerations. Although many shape memory alloy (SMA) heat engines have been proposed to harvest this energy, and a few have been built and demonstrated in past decades, they have not been commercially successful. Some of the barriers to commercialization include their perceived low thermodynamic efficiency, high material cost, low material durability, complexities when using fluid baths, and the lack of robust constitutive models and design tools. Recent advances, however, in SMA longevity, reductions in materials costs (as production volumes have increased), and a better understanding of SMA behavior have stimulated new research on SMA heat engines. The Lightweight Thermal Energy Recovery System (LighTERS) is an ongoing ARPA-E funded collaboration between General Motors, HRL Laboratories, Dynalloy, Inc., and the University of Michigan. In the LighTERS engine (a refinement of the Dr. Johnson engine), a closed loop SMA spring element generates mechanical power by pulling itself between alternating hot and cold air regions. The first known thermo-mechanical model for this type of heat engine was developed in three stages. First, the constitutive and heat transfer relationships of an SMA spring form were characterized experimentally. Second, those relationships were used as inputs in a steady-state model of the heat engine, including both convective heat transfer and large-deformation mechanics. Finally, the model was validated successfully against measurements of a experimental heat engine built at HRL Labs.

1914 New type stents using shape memory alloy

2005 ◽  
Vol 2005.1 (0) ◽  
pp. 481-482
Author(s):  
Kiyoshi YAMAUCHI ◽  
Yuji SUTOU ◽  
Takamitu TAKAGI ◽  
Toshio SAKUMA
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
New Type
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