Multichannel Energy Harvesting Electronic Device for Structural Health Monitoring Systems

In this paper, the design, implementation and testing of a prototype for electric energy generation by collecting wasted ambient power sources coming from the mechanical vibrations (Piezoelectric Energy Harvesting PEH) is presented. This prototype has been specifically designed for applications where it is required to connect multiple transducers in order to obtain greater power levels. This design is based on a previous comparative performance analysis among all the existing autoharvesting circuits. The prototype has been tested in laboratory tests, with encouraging results. It has been proved that, though achieving power levels of a few milliwatts, the developed prototype has a significant potential for powering autonomous lowconsumption devices, such as Structural Health Monitoring (SHM) systems and other avionic sensors distributed in the structures of the aircrafts. A new integrated electronic device called PEH-PM24 (Piezoelectric Energy Harvester Power Management 24 channels) has been designed with capacity for 24 channels. The PEH-PM24 electronic system can be configured in many modes in order to obtain more or less voltage or current, in function of the number of piezoelectric transducers connected to the device or in function of the disposal of those transducers. One advantage of using these piezoelectric transducers is that they can be connected among themselves both in serial and in parallel configuration. In order to verify the appropriate operational performance of the manufactured electronic device, vibration tests have been carried out using several piezoelectric transducer sets. These tests have been performed in two separated stages. The first one was by employing only one transducer and the second with multiple transducers simultaneously. The experimental tests have been performed using a shaker where the piezoelectric transducers were placed in a cantilever configuration. Tests performed with multiple piezoelectric tuned transducers have been carried out in a mechanizing center yielding encouraging results. At present, research efforts are leaded to optimize the size, number and position of multiple transducers in large structures such as aircraft components.