Immobilisation has been one of the common forms of treatments for orthopaedic injuries and diseases. Immobilisation of injured limbs using dynamic splinting is routinely recommended by clinicians for fast healing as it promotes blood flow and provides the require stability. There are several dynamic splints available in the market that make use of different materials and mechanical elements. This research was set out to investigate the applicability of Magneto-Rheological(MR) fluids for the development of a smart fabric for orthopaedic splints. The fabric would be woven with hollow fibres containing MR fluid, which will change stiffness in an applied magnetic field. The concept was tested by measuring changes in the stiffness of silicone tubings in two different diameters filled with MR fluid, under different magnetic flux densities. The corresponding changes in stiffness of a preliminary fabric specimen built with woven tubings and cast liner was also investigated. The magnetic field was created after a set of detailed experimental and numerical analyses (Finite Element Method). It was found that although the electromagnets are much more versatile and easier to control for a required magnitude of magnetic flux density, they were found to be unsatisfactory due to their weight, bulk, and substantial requirement of batterie power. Permanent magnets offered a much better solution. After detailed preliminary analyses, an array of 21 neodymium magnets was chose for the experiments, which provided the required magnitude and uniformity of the magnetic field. The specimens were loaded in steps by small weights, and the resulting deflection was measured using an optical deformation analysis system. The equivalent Young’s modulus was found to increase from 16 MPa to 122 MPa under an average magnetic flux density of 0.0139 Tesla, which is an in- crease of 70%. A finite-element (FE) model of the single tubing test set up was developed and validated against the experimental results. The FE analysis was extended to the fabric specimens. The difference between the experimental and numerical results for the single tubing was as small as 2.5%, and 9.2% for the fabric. Furthermore, a preliminary numerical model and analysis of the hand was developed, which set the basis in the development of a further numerical analysis in the final development of the fabric. Upon the completion of the tests and simulation, it was concluded that a woven fabric made up of hollow fibres containing MR fluid can be an effective dynamic splint over a small area such as the wrist. However a fully functional product would require further research.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:668568 |
| Date | January 2015 |
| Creators | Garcia Garcia, Leonardo Azael |
| Publisher | University of Manchester |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://www.research.manchester.ac.uk/portal/en/theses/development-of-a-smart-fabric-for-orthopaedic-applications(58882d64-9605-4533-9a32-38e628a05cfd).html |
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