Non-intrusive movable energy harvesting devices: Materials, designs, and their prospective uses on transportation infrastructures

As low-carbon and smart cities are recently developing fast, non-intrusive and movable energy harvesters can be a trend of energy harvester development to face the severe climate change and to follow the fast pace of urban development and energy needs. To study the feasibility of developing non-intrusive and movable energy harvesters within the limit area available on transportation infrastructures (e.g., roadway, bridge, pipeline), advanced energy materials and the innovative energy harvester designs have been extensively reviewed, identified, and analzyed. For the energy material selection, the review covers the development of photovoltaic materials, thermoelectric materials, piezoelectric materials, and pyroelectric materials. It shows significant relevant progresses, which have reached the theoretical limitations of their energy harvesting performance. On the other side, this review collects a series of relevant innovative designs, including concentrating solar power devices, portable solar panels, horizontal wind turbines, piezoelectric-based (or pyroelectric-based) wind energy harvesters, and vibration-based piezoelectric harvesters. Based on their sizes, power outputs, and external environmental requirements, it is clear that some non-intrusive and movable energy harvesters can be quickly implemented on transportation infrastructures for producing considerable power outputs. As a result, through critically assessing current developments of all relevant advanced materials with innovative designs, a new research direction is explored to develop movable and non-intrusive energy harvesters suitable for transportation infrastructures.