Abstract

Background: Exoskeletons are mechanical devices used in rehabilitation to enhance human joint movements for individuals suffering from debilitating neurological or limb pathologies lacking sufficient strength, power, torque, and endurance. The cost for standard exoskeletons used for gait rehabilitation and mobility assistance is ridiculously high. This has made such assistive devices, which could impact the quality of life of individuals with disability unattainable.
Objective: The aim is to evaluate four natural materials with the hope to replace the currently used duralumin and thereby reduce the cost of exoskeleton.
Methods: A two-step analyses process was utilized. First, gait cycle kinematics of normal walking was analyzed and used to determine the minimum loading requirements for the replacement material. The information provided the basis for the assessment of the mechanical properties of four natural construction materials, fir, pine, oak and bamboo used in this study. Secondly, Granta CES Selector software was used to assess the cost, mechanical properties and viability of these natural materials with the view of replacing duralumin with them.
Results: Analysis of gait cycle kinematics showed that the energy expenditure and loading requirement for walking was highest at mid-stance. All the four natural materials studied satisfied strength and elasticity requirements as dictated by duralumin and the gait analysis. However, bamboo exhibits additional excellent characteristics, such as lightweight, bending, and toughness.
Conclusion: Although the four natural materials satisfied the yield strength requirements but only bamboo can be used as replacement material for duralumin. Bamboo with additional characteristics of bending and toughness make it more favorable replacement material for the design of exoskeleton.