Fluid coupling interfaces for hydraulic pressure energy harvesters

The need for wireless sensor networks that can run for long times without the need of battery replacement has risen the need for energy harvesters. Industrial environments have plenty of energy sources that can be harvested; pressure fluctuations are a high energy density source that can be harvested using piezoelectric devices. Present devices have introduced flat metallic plates as the main force transmission elements for hydraulic fluctuations energy harvesters. In this paper, we analyze the force transmission efficiency of flat plates when used as the primary fluid coupling interface in hydraulic energy harvesters. Previous work has been focused on the optimization of circuit matching and pressure ripple amplification. In this work, we offer a look into the efficiencies of flat plates in different configurations and pressure loads. The analysis shows that despite the reasonable force transmission efficiency of flat plates in low-pressure environments, the overall efficiency of hydraulic energy harvesters can be improved if instead of flat plates, conventional hydraulic actuators, such as piston cylinders, could be used.