Electro-Thermo-Mechano-Magneto Characteristics of Shape Memory Spring Actuator/Sensor in Assistive Devices

  • T. Devashena
  • K. DhanalakshmiEmail author
Conference paper
Part of the Advances in Intelligent Systems and Computing book series (AISC, volume 1077)


In recent years, shape memory alloys (SMAs) have been used widely as actuators in modern systems but it can also be used as sensor since it offers unique self-sensing property. Shape memory alloys exhibit parameter variations that include electrical properties such as resistance in case of SMA wire and impedance in case of SMA spring, as a nonlinear hysteretic behavior within a transformation cycle. The actuation and sensing characteristics of SMA can be obtained from the material’s electromechanical impedance. This work presents about the electro-thermo-mechano-magneto effects exhibited in commercially available NiTiNOL spring with 90 °C phase transition temperature during phase transformation. The phase-dependent electrical resistance, inductance, impedance, and magnetic field of the SMA spring is measured using impedance analyzer and milli gauss meter respectively. The results opens the door to a new dimension of application of SMA spring, i.e., the investigation explores a possibility for the design of electro-thermo-mechano-magneto characteristics based assistive systems and in robotics.


NiTi spring Joule heating Temperature Displacement Force Magnetic field Electrical resistance Series inductance Duty cycle 


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Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Department of Instrumentation and Control EngineeringNational Institute of Technology, TiruchirappalliTiruchirappalliIndia

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