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35 Hz shape memory alloy actuator with bending-twisting mode.

Song SH, Lee JY, Rodrigue H, Choi IS, Kang YJ, Ahn SH - Sci Rep (2016)

Bottom Line: The actuation characteristics of the actuator at different frequencies are measured with different actuator lengths and results show that resonance can be used to realize large deformations up to 35 Hz.A model is used to compare with the experimental results of actuators with different layered reinforcement structure designs.Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10 Hz is also realized.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical &Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.

ABSTRACT
Shape Memory Alloy (SMA) materials are widely used as an actuating source for bending actuators due to their high power density. However, due to the slow actuation speed of SMAs, there are limitations in their range of possible applications. This paper proposes a smart soft composite (SSC) actuator capable of fast bending actuation with large deformations. To increase the actuation speed of SMA actuator, multiple thin SMA wires are used to increase the heat dissipation for faster cooling. The actuation characteristics of the actuator at different frequencies are measured with different actuator lengths and results show that resonance can be used to realize large deformations up to 35 Hz. The actuation characteristics of the actuator can be modified by changing the design of the layered reinforcement structure embedded in the actuator, thus the natural frequency and length of an actuator can be optimized for a specific actuation speed. A model is used to compare with the experimental results of actuators with different layered reinforcement structure designs. Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10 Hz is also realized. By increasing their range of actuation characteristics, the proposed actuator extends the range of application of SMA bending actuators.

No MeSH data available.


Related in: MedlinePlus

Setup and methods for observing the performance of the actuator.(a) Experimental setup, (b) Measurement of the tip deformation and (c) flapping angle.
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f4: Setup and methods for observing the performance of the actuator.(a) Experimental setup, (b) Measurement of the tip deformation and (c) flapping angle.

Mentions: The actuator’s length and its deformation magnitude are closely related since the deformation of the actuator is larger at a fixed radius of curvature for a longer actuator length. However, for high speed actuation, this might not be the case due to interaction with its environment and due to the decreased natural frequency associated with a longer length of the actuator. Furthermore, since the temperature and the deformation are coupled rather than the voltage and the deformation, the cooling time might have an effect on the maximum actuation angle. To verify these relations, experiments are conducted to measure the relation between the actuator’s length and its actuation frequency as in Fig. 4.


35 Hz shape memory alloy actuator with bending-twisting mode.

Song SH, Lee JY, Rodrigue H, Choi IS, Kang YJ, Ahn SH - Sci Rep (2016)

Setup and methods for observing the performance of the actuator.(a) Experimental setup, (b) Measurement of the tip deformation and (c) flapping angle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4759690&req=5

f4: Setup and methods for observing the performance of the actuator.(a) Experimental setup, (b) Measurement of the tip deformation and (c) flapping angle.
Mentions: The actuator’s length and its deformation magnitude are closely related since the deformation of the actuator is larger at a fixed radius of curvature for a longer actuator length. However, for high speed actuation, this might not be the case due to interaction with its environment and due to the decreased natural frequency associated with a longer length of the actuator. Furthermore, since the temperature and the deformation are coupled rather than the voltage and the deformation, the cooling time might have an effect on the maximum actuation angle. To verify these relations, experiments are conducted to measure the relation between the actuator’s length and its actuation frequency as in Fig. 4.

Bottom Line: The actuation characteristics of the actuator at different frequencies are measured with different actuator lengths and results show that resonance can be used to realize large deformations up to 35 Hz.A model is used to compare with the experimental results of actuators with different layered reinforcement structure designs.Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10 Hz is also realized.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical &Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.

ABSTRACT
Shape Memory Alloy (SMA) materials are widely used as an actuating source for bending actuators due to their high power density. However, due to the slow actuation speed of SMAs, there are limitations in their range of possible applications. This paper proposes a smart soft composite (SSC) actuator capable of fast bending actuation with large deformations. To increase the actuation speed of SMA actuator, multiple thin SMA wires are used to increase the heat dissipation for faster cooling. The actuation characteristics of the actuator at different frequencies are measured with different actuator lengths and results show that resonance can be used to realize large deformations up to 35 Hz. The actuation characteristics of the actuator can be modified by changing the design of the layered reinforcement structure embedded in the actuator, thus the natural frequency and length of an actuator can be optimized for a specific actuation speed. A model is used to compare with the experimental results of actuators with different layered reinforcement structure designs. Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10 Hz is also realized. By increasing their range of actuation characteristics, the proposed actuator extends the range of application of SMA bending actuators.

No MeSH data available.


Related in: MedlinePlus