Kinetic energy is the most natural form of energy available, and one that if harvested to its full potential could save the world from its energy woes. Evident in many different guises from radiant, sound, thermal, electrical (light), mechanical (motion), vibrations, and rotational, kinetic energy has been hailed as the future energy source.
According to Innovation Spotlight, wearable devices will one day not only be used to extract vibration energy to charge their own batteries, but they could make a bold impact on society by using that energy to power other electronics.
A group of international researchers from the University of New South Wales and the University of Queensland have experimented with kinetic energy harvesting and see it as “a valuable tool for things like urban planning and development by detecting people’s modes of transportation.”
According to Sara Khalifa, a researcher from Data61|CSIRO, Australia, transportation mode detection is important to our communities: “It allows researchers to consistently and reliably collect information on individuals’ traveling behavior to inform urban design, real-time journey planning, human activity monitoring, CO2 emissions, targeted advertising and more”.
The system has been developed as a sophisticated monitoring tool for communities. It can detect potential hazards, provide emergency services with information for the fastest route to a serious accident and more.
Kinetic energy harvesting converts environmental kinetic or vibration energy (wind, waves, vehicle movement, machinery vibration, human motion) into electrical energy that can be used to power low-energy electronics.
According to Innovation Spotlight, the researchers proposed “using kinetic energy harvesting’s output voltage as the source for detecting transportation mode. This concept is based on the idea that the vibration energy experienced by a passenger are different depending on the transportation used (walking, running, bus, driving, etc.)”.
“This means different vibration patterns generate different AC voltage patterns, which can yield clues as to transportation mode”
Using piezoelectric material which converts the kinetic energy to electric power, when “the mechanism is subject to stress from environmental vibrations, it generates an AC voltage proportional to the applied stress. This means different vibration patterns generate different AC voltage patterns, which can yield clues as to transportation mode”.
The study went on to detail how the voltage generated by the wearable records distinctive differences between the user’s transportation mode. According to the report “researchers were able to achieve 98.84 percent accuracy in determining whether the user was walking/running or in a motorized vehicle. Overall accuracy of classification between motorized vehicles (bus, car, train) was over 85 percent. At the same time, kinetic energy harvesting allowed these wearable detecting devices to stay fully powered.”
While this research looked at the transportation device the user is inside to generate electricity, there are also other extensive studies being conducted that look at human activity recognition, step counting, calorie expenditure estimation, user authentication and train route identification.