Evaluation of the mechanical characteristics of human thighs for developing complex dummy tissues

Wearable robots pose high risks to humans because they are directly mounted on human bodies, and methods for assessing their safety have not yet been established. For developing such safety tests, we have fabricated dummy legs that emulate the structure of the human body. Furthermore, all mechanical characteristics of human tissues that relate to their interactions with a wearable robot - elasticity, viscosity, normal stress, deformation, and friction coefficient - must be considered in parallel. Moreover, complex dummy tissues were developed and their characteristics were compared with those of human tissues. Mechanical characteristics of tissues for both humans and dummy were evaluated using a rheometer and an ultrasonic probe to clarify the similarities or differences. Consequently, we identified a mechanism of biological soft tissues as well as a way of imitating these characteristics in complex dummy tissues.