Smart-shoes self-powered by walking

Nowadays, electronic devices are more and more compact and can be integrated in nearly every object. One of the remaining challenges is to provide smarter ways to power those electronic devices. Because of the small amount of energy needed by the latest ultra-low power systems, energy harvesting from the environment becomes a viable solution to power them. In this work, we present the integration of an electronic device and an electrodynamic energy harvester (EH) in a shoe. The electronic device measures the acceleration along one axis at a sampling rate of 30 Hz and sends the data every second using a wireless link. The data are then collected by a gateway and processed to count the number of steps, calculate the contact time and the flying time of the foot. To perform this function, the device requires an average power of 951 μW which is provided by the EH.