Design and Evaluation of Double-Stage Energy Harvesting Floor Tile

Abstract

This paper introduces the design and characterization of a double-stage energy harvesting floor tile that uses a piezoelectric cantilever to generate electricity from human footsteps. A frequency up-conversion principle, in the form of an overshooting piezoelectric cantilever, plucked with a proof mass is utilized to increase energy conversion efficiency. The overshoot of the proof mass is implemented by a mechanical impact between a moving cover plate and a stopper to prevent damage to the plucked piezoelectric element. In an experiment, the piezoelectric cantilever of a floor tile prototype was excited by a pneumatic actuator that simulated human footsteps. The key parameters affecting the electrical power and energy outputs were investigated by actuating the prototype with a few kinds of excitation input. It was found that, when actuated by a single simulated footstep, the prototype was able to produce electrical power and energy in two stages. The cantilever resonated at a frequency of 14.08 Hz. The output electricity was directly proportional to the acceleration of the moving cover plate and the gap between the cover plate and the stopper. An average power of 0.82 mW and a total energy of 2.40 mJ were obtained at an acceleration of 0.93 g and a gap of 4 mm. The prototype had a simple structure and was able to operate over a wide range of frequencies.

Impact-Driven Energy Harvesting: Piezoelectric Versus Triboelectric Energy Harvesters

“…For calculating the total energy harvested , the equation was Equation (2), where was the total time while the triboelectric was working was the voltage across the resistive load at a time and was the sampling time interval. We used these equations in the same way that they were used in [ 12 , 13 ]: and …”

“…On the other hand, the second type of test bench had a simple structure and a higher electrical performance than the first type because electrical energy was generated each time the cover plate was pressed and each time it was released. In another study, Don Isarakorn et al [ 13 ] investigated the behavior of double-stage energy harvesting floor tile. They varied the excitation acceleration and gap width of the cover plate, observed the results, and found that the accelerations of the moving cover plate and gap width were directly proportional to the electrical output.…”

A Systematic Review of Piezoelectric Materials and Energy Harvesters for Industrial Applications

“…An increase in the gap steadily increases the energy output, but a larger gap can make walking on the tiles too uncomfortable. Hence, the gap width should be optimized between high energy generation and comfortable walking [ 109 ]. The buoy is an aerologic device that is restricted to heave motion only.…”

“…Hence, the gap width should be optimized between high energy generation and comfortable walking [109]. 4.…”

Technique for Measuring Power across High Resistive Load of Triboelectric Energy Harvester

“…The optimal value for load resistance can be determined by trying out a range of values for load resistance R L and picking the one that provides the maximum power transfer or extrapolating to the best value from the value that provided the maximum power transfer in the try-out. Equivalently, we can determine a range of values for the internal resistance R int from the achieved maximum or near maximum power transfer by varying the values of the load resistance R L and use a value (exact or extrapolated) in the range to determine the optimal load resistance [ 3 , 4 , 5 , 6 ].…”