The continuous homogeneous rail constraint of embedded rail system (ERS) is realized by the encapsulation of rails with the elastic poured compound (EPC) which is a composite material. Previous treatment of EPC as linear elastic material was insufficient in the failure analysis of ERS. In this work, a hyperelastic model is developed to describe the mechanical properties of the EPC with engineering strain up to 150%. Physical tests of uniaxial tension, planar tension and quadruple shear are conducted. A 4-parameter Ogden model is determined by curve fitting and validated with a progressive validation strategy, and then is applied to the failure analysis of ERS. It is found that the material nonlinearity of EPC contributes noticeably to the decrease of the longitudinal stiffness of ERS. The 2^nd debonding is more probably caused by the failure of adhesive at the interface between EPC and rail rather than EPC itself.

Body Channel Communication (BCC) offers a low-loss signal transmission medium for ultra-low-power wearable devices on human body [1]. However, the effective communication range on human body is limited to less than 1m in the state-of-the-art BCC transceivers [2], where the signal loss at the interface of body surface and BCC receiver remains to be one of the main bottlenecks. The limited communication range has blocked the popularization in many WBAN applications, such as signal transmission from to an intelligent insole to smart watch [3]. Relative to the high impedance of human body [4], the lower input impedance of BCC receiver induces significant signal loss. To reduce the interface loss, conventional interface front end (IFE) of BCC receivers was designed to be with a high input impedance [5], but the DC voltage bias decreased both the input impedance and signal gain of IFE.