Within the past 15 years, significant advances in semiconductor integrated circuits (ICs) have reduced power consumption requirements such that mechanisms of transducing various forms of ambient energy for providing autonomous power are a viable technology. The field of energy harvesting has grown immensely as new solutions for developing self-sustaining wireless sensor networks for applications such as structural health monitoring (SHM), precision viticulture, and biometric wearable devices are continually investigated. Due to the wide variety of energy transduction methods and the inherent multidisciplinary nature of energy harvesting, a systematic paradigm for the capture and use of ambient energy is presented. The research outlined in this dissertation covers two energy transduction mechanisms : electrochemical energy harvesting, and vibration energy harvesting. The first project presented details the modeling, development and testing of a novel cement sea- water battery (C-SWB) and a complimentary low-power sensor node designed for long-term marine infrastructure health monitoring. The second project investigates analytically and experimentally the augmented broadband vibration energy capture of a modulated inertial generator (MIG). Closed-form analytical expressions of interacting electromagnetic dipole moments are derived and used as a nonlinear control parameter to modulate the response of an inertial generator to expand the resonant frequency response spectrum