Title: Wearable Assistive Materials
Funder: Engineering and Physical Sciences Research Council

Abstract: WAM is a project which started from asking a question about what would make a transformational difference to someone who is experiencing difficulties in walking. The answer was to be able to walk without visible (or audible) assistance. Following some initial work in an EPSRC project called RELEASE, WAM is starting on the road to developing just this sort of assistive technology: an exoskeleton that can be worn and that can also act as a muscle so that it can support the whole walking cycle, providing support and control to the user and enabling them to walk otherwise unaided. We have selected some of the likely possibilities from those explored during the RELEASE project and WAM will develop these further, combine them and test them against the strength, stiffness, flexion and strain requirements of the walking process. Three technologies will be explored in parallel: (1) using Vanadium Oxide (V2O5) as a chemical actuator, (2) using magnetic gels as a dynamic controllable mechanism and (3) using interlockable ceramic tiles as a surface medium. V2O5 is able to flex when exposed to an electrostatic potential and can exhibit strength (about 10 times the strength found in skeletal muscle) so this would seem to be a useful substance to use as the basis for an actuator. Macroporous magnetic gels can be used to compress rapidly under a magnetic field to deliver drugs (by squeezing the drugs from the pores as the material compresses under the influence of an induced magnetic field). Interlockable ceramic tiles can provide the stiffness needed for the rigidity needed by a skeleton, but once unlocked an allow the structure to bend in a required direction. These will be tested separately and in combination to see if the V2O5 working with the magnetic gel could act as a sufficiently strong actuator and key for the locking/unlocking mechanism so that the material can demonstrate sufficient strength, stiffness and strain capabilities to be worth scaling up in a future project to assist walking. Other possibilities would also be available from such material - it does not have to be used only for walking as it could be used for other joints which can need support but which also need to bend - elbow, wrist, ankle as well as knee are all candidates for such support. Also, it might provide an interesting support where it is desirable to make the assistance variable - when the person needs support and when they would benefit from being encouraged to take on the activity themselves. A variably flexible material of this sort would therefore be of use in conditions such as limb fractures (where absolutely fixed support is essential at one point on the process, but rehabilitation of associated muscles would be beneficial as the facture is healing, but is still weak, before the fixed support can be removed) or conditions such as Carpal Tunnel Syndrome where support needs might vary. While the technological work is underway we will be working with a patients' group and a group of clinicians to understand more about what end users might be looking for in their assistive technology and how this particular type of support might be useful for them. It is important to realise that this is a novel way of providing dynamic support for activities such as walking and thus there is a sense of all sides needing to understand how best to use the technology as it emerges from the laboratory. The present project will not deliver the full working prototype of a walking support system, but it will develop, test and show what can be done in terms of the material and its control system and the extent to which this approach to actuation of locomotory support could be achieved. The final tests will show how much stiffness and strength it can deliver and thus whether or not this is the right way to proceed in further projects.


Research activity codes: 5.3 MEDICAL DEVICES
Health categories: MUSCULOSKELETAL