High-Performance Single and Polycrystal-Based Pyroelectric Smart Materials for Energy Harvesting from Pavements

Energy-harvesting (also known as power harvesting or energy scavenging) technology allows for capturing unused ambient energy—such as solar, thermal, strain, and vibration—and converting the energy to a usable form. The goal of this study was to determine whether the possibility of capturing thermal energy derived from natural heating of pavements, storing the energy, and using it as an alternative power source for other devices. In this study, pyroelectric materials were used as the energy harvester. A change in temperature creates current flows in pyroelectric material. Single and polycrystal-based materials and a polycrystalline composite material based on ordinary portland cement with carbon nanofibers have been used as pyroelectric smart materials. Smart material based on portland cement can capture ambient thermal energy from pavements. When carbon nanofibers are added, the cement-based composite acts as a pyroelectric material. Addition of carbon nanofibers increases the pyroelectric properties of cement. Simulation of the energy-harvesting capacity of the materials with available pavement temperature data indicates that pyroelectric energy harvesting is an attractive and feasible method. Laboratory tests indicate that smart materials can produce enough electricity from traffic vibrations to power wireless bridge sensors. Simple material such as portland cement can be used to capture heat energy from pavements, which can be stored in capacitors for use as power sources to other sensor electronics.