Thermo-magnetic shape control of nano-ferromagnetic particle doped shape memory alloy for orthopedic devices and rehabilitation techniques

Abstract

Recent advancement in smart materials facilitated the use of Shape Memory Alloy(SMA) in treatment of different orthopedic problems and rehabilitation technique to treat paralyzed patients. But Shape Memory alloy lacks the controllability while regaining the shape from martensite to austenite during thermal loading. Therefore, in this paper we introduced a mechatronic device which provides the control over the shape change of new hybrid material having property of SMA and shape memory property of anticipated material is verified by finite element analysis in COMSOL Multiphysics. In the proposed methodology the shape is controlled by generating a controlled thermo-magnetic loading, and hybrid material formed by doping a nano-ferromagnetic particle in porous NiTi SMA. For the proof of the concept an experiment is carried out by using a bimetallic strip, microcontroller, sensor and proper feedback circuitry system and it is observed that for the supply of 4V and bent angle for flex sensor between 0 to 40 degree, current through the solenoid is 3.63A producing Magnetic field of 1.42mT and for flex sensor b ent angle 4 0 to 7 5 degree the current through the solenoid is 1.2A producing Magnetic field of 0.47mT for same supply and if the flex sensor bent angle increases more than 75 degree then the voltage supply cutoffs which indicate the absence of Magnetic field.