Abstract

Energy harvesting, which converts ambient, otherwise wasted, energy sources into usable electricity, is expected to contribute to the formulation of a self-generating power grid. This type of grid can enable sustainable operation of wireless sensor networks as the “Smart City” vision becomes reality. Human walking is a plentiful mechanical energy source wasted during daily activities. This study aims to develop an omnidirectional biomechanical energy harvesting (OBEH) sidewalk block that is able to generate electricity from human walking. Here, a systematic design framework for the OBEH sidewalk block is presented; it consists of three important ingredients, specifically: (1) extraction of a footstep loading profile from human gait analysis; (2) electroelastically coupled finite element modeling to estimate the transient output responses under the footstep loading profile; and (3) reliability-based design optimization of the OBEH sidewalk block. This study considers two kinds of the inherent randomness, including (1) variability in the material properties and geometry; and (2) uncertainty in the position and direction of the footsteps. It can be concluded from the results that the optimum design of the proposed OBEH sidewalk block enables useful power generation while satisfying the target reliability of fatigue failure in the presence of the inherent randomness.