Shape Memory Alloys (SMA’s)OutlineOutline (cont.)References:To Explore Further……..Major ApplicationsWhat is Shape Memory Alloy?Meaning What ?????How does this work???In other words…Major specificationsA Typical use: The Smart WingA Typical use: The Smart WingAnother use: Robotic MusclesAnother use: Robotic MusclesAdvantages:LimitationsWho sells this :What materials are SMA’sTo Conclude……..Shape Memory Alloys (SMA’s)Daniel FreiUtah State UniversityECE 5320March 5, 2004OutlineReferencesTo Explore FurtherApplicationWhat is Shape Memory AlloyHow does it workMajor SpecificationsA Typical use: The Smart WingAnother use: Robotic MusclesOutline (cont.)AdvantagesLimitationsWho sells this?What materials are SMA’s?ConclusionReferences:http://www.cs.ualberta.ca/~database/MEMS/sma_mems/sma.htmlhttp://smart.tamu.edu/http://www.reade.com/Products/General/shape_memory_alloys.htmlhttp://www-civ.eng.cam.ac.uk/dsl/sma/smasite.htmlhttp://www.fz-juelich.de/iwv/iwv1/index.php?index=65http://www.sma-inc.com/html/_shape_memory_alloys_.htmlTo Explore Further……..http://smart.tamu.edu/http://www.cs.ualberta.ca/~database/MEMS/sma_mems/sma.htmlhttp://www.designinsite.dk/htmsider/m1310.htmhttp://www.sma-inc.com/html/johnson_matthey_home_page.htmlhttp://www.reade.com/Products/General/shape_memory_alloys.htmlhttp://www-civ.eng.cam.ac.uk/dsl/sma/smasite.htmlhttp://www.fz-juelich.de/iwv/iwv1/index.php?index=65http://www.sma-inc.com/html/_shape_memory_alloys_.htmlhttp://www.mtm.kuleuven.ac.be/Research/ADAPT/index.htmlhttp://dpwww.epfl.ch/Gotthardt/groupegt.htmlMajor ApplicationsCoffeepots The space shuttle Thermostats Vascular Stents Hydraulic Fittings (for Airplanes) Used in the followingMedical ToolsEyeglass Frames Bra Under wires Cellular Phone Antennae Orthodontic ArchesWhat is Shape Memory Alloy?“Shape memory alloys (SMA's) are metals, which exhibit two very unique properties, pseudo-elasticity, and the shape memory effect. Arne Olander first observed these unusual properties in 1938 (Oksuta and Wayman 1998), but not until the 1960's were any serious research advances made in the field of shape memory alloys. The most effective and widely used alloys include NiTi (Nickel - Titanium), CuZnAl, and CuAlNi.”From: http://www.cs.ualberta.ca/~database/MEMS/sma_mems/sma.htmlMeaning What ?????Shape Memory Alloys are Really Just a “smart” material that returns to it’s Normal shape and size after something like heat has manipulated it.Picture From: http://smart.tamu.edu/How does this work??? “The two unique properties described above are made possible through a solid state phase change, that is a molecular rearrangement, which occurs in the shape memory alloy. Typically when one thinks of a phase change a solid to liquid or liquid to gas change is the first idea that comes to mind. A solid state phase change is similar in that a molecular rearrangement is occurring, but the molecules remain closely packed so that the substance remains a solid. In most shape memory alloys, a temperature change of only about 10°C is necessary to initiate this phase change. The two phases, which occur in shape memory alloys, are Martensite, and Austenite. Martensite, is the relatively soft and easily deformed phase of shape memory alloys, which exists at lower temperatures. The molecular structure in this phase is twinned which is the configuration shown in the middle of Figure 2. Upon deformation this phase takes on the second form shown in Figure 2, on the right. Austenite, the stronger phase of shape memory alloys, occurs at higher temperatures. The shape of the Austenite structure is cubic, the structure shown on the left side of Figure 2. The un-deformed Martensite phase is the same size and shape as the cubic Austenite phase on a macroscopic scale, so that no change in size or shape is visible in shape memory alloys until the Martensite is deformed.”http://www.cs.ualberta.ca/~database/MEMS/sma_mems/sma.htmlIn other words…When the material is in the heated phase know as the Martensite it is easy to move and manipulate. Once it has cooled then it is in the Austenite phase and can retains the shape it is given. Size and metal characteristics do not change throw these processes. Pictures from: http://www.cs.ualberta.ca/~database/MEMS/sma_mems/flap.htmlMajor specificationsMust be a SMACritical Tempature (50°C-80°C)Transformation Temperature Range (-250°C to 200°C depending on the material)Transformation Hysteresis (4°C to 100°C)A Typical use: The Smart WingA Typical use: The Smart Wing The smart is a new technology that uses Shape memory alloys to Change the Shape of the Wing of a Plane to make it more maneuverable. This is done by simply sending a electric current throw the part of the plane to heat it to the desired temperature. This changes the shape of the wing making the Plane more maneuverable. This was previously done with a heavy Hydraulic system, thus significantly reducing the weight of the plane. This is demonstrated to the right. Pictures from: http://www.cs.ualberta.ca/~database/MEMS/sma_mems/flap.htmlAnother use: Robotic MusclesAnother use: Robotic MusclesOne of the biggest problems with robots simulating Human behavior is that they have difficulting with the simulation of our muscle and basic movements. Things like holding a pen or a pencil, feeling/touch, or just moving a finger are great challenges for Robotics. With Shape memory alloys work and simulate human muscle very well. When the heat of a wire changes the shape and move ability of the metal. This is similar to a muscle as a nerve send a pulse to the muscle the size doesn’t change, however it does weaken or strengthen to accommodate the need of the movement. Pictures is from: http://www.cs.ualberta.ca/~database/MEMS/sma_mems/muscle.htmlAdvantages:Bio-compatibility Diverse Fields of Application Good Mechanical Properties (strong, corrosion resistant)Limitationsexpensive to manufacture fatigue properties (twisting, bending, compressing)Extreme Heat and coldMust be a SMAYOUR IMAGINATIONWho sells this : http://www.sma-inc.com/html/johnson_matthey_home_page.htmlhttp://www.memory-metalle.de/shape-memory-alloy.htmlhttp://content.aip.org/APPLAB/v84/i1/31_1.htmlWhat materials are SMA’sa.)Nickel-titanium alloysb) Copper-base alloys such as CuZnAl and
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