Wearable Assistive Materials

WAM是一个项目，它开始于问一个问题，什么能给那些行走困难的人带来翻天覆地的变化。答案是能够在没有视觉（或听觉）帮助的情况下行走。在EPSRC项目RELEASE的一些初步工作之后，WAM正开始开发这种辅助技术：一种可以穿着的外骨骼，也可以作为肌肉，这样它就可以支持整个行走周期，为用户提供支持和控制，使他们能够在没有帮助的情况下行走。我们从RELEASE项目中选择了一些可能的可能性，WAM将进一步开发这些可能性，将它们结合起来，并根据步行过程的强度、刚度、屈曲和应变要求进行测试。三种技术将并行探索：(1)使用氧化钒（V2O5）作为化学致动器，(2)使用磁凝胶作为动态可控机制，(3)使用可互锁瓷砖作为表面介质。V2O5在暴露于静电电位时能够弯曲，并且可以表现出强度（大约是骨骼肌强度的10倍），因此这似乎是一种有用的物质，可以用作执行器的基础。大孔磁性凝胶可用于在磁场下快速压缩以输送药物（在感应磁场的影响下，当材料压缩时，将药物从孔中挤压出来）。可互锁的瓷砖可以提供骨架所需的刚度，但一旦解锁，就会允许结构向所需的方向弯曲。这些材料将分别进行测试，并将进行组合测试，以确定与磁性凝胶一起工作的V2O5是否可以作为足够强大的致动器和锁定/解锁机制的钥匙，从而使材料能够展示足够的强度、刚度和应变能力，值得在未来的项目中扩大规模，以辅助行走。这种材料也有其他的可能性——它不仅可以用于行走，还可以用于其他需要支撑但也需要弯曲的关节——肘部、手腕、脚踝和膝盖都是这种支撑的候选者。此外，它可能会提供一种有趣的支持，当人们需要帮助的时候，当他们从鼓励自己进行活动中受益的时候，帮助是可变的。因此，这种可变柔性材料将用于诸如肢体骨折（在过程的某一点上绝对固定的支撑是必不可少的，但在固定支撑可以移除之前，骨折正在愈合，但仍然脆弱，因此相关肌肉的康复将是有益的）或腕管综合征等条件，其中支持需求可能会变化。当技术工作正在进行时，我们将与患者小组和临床医生小组合作，更多地了解最终用户可能在他们的辅助技术中寻找什么，以及这种特殊类型的支持如何对他们有用。重要的是要认识到，这是一种为步行等活动提供动态支持的新方式，因此各方都需要了解如何最好地利用这项从实验室出来的技术。目前的项目不会提供行走支撑系统的完整工作原型，但它将开发、测试并展示在材料及其控制系统方面可以做些什么，以及这种驱动运动支撑的方法可以实现的程度。最终的测试将显示它能提供多少刚度和强度，从而判断这是否是在进一步项目中进行的正确方法。

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.