State of the art in acoustic energy harvesting

Abstract

For portable and embedded smart, wireless electronic systems, energy harvesting from the ambient energy sources has gained immense interest in recent years. Several ambient energies exist in the environment of wireless sensor nodes (WSNs) that include thermal, solar, vibration and acoustic energy. This paper presents the recent development in the field of acoustic energy harvesters (AEHs). AEHs convert the acoustic energy into useful electrical energy for the operation of autonomous wireless sensors. Mainly, two types of AEHs (electromagnetic and piezoelectric based) have been developed and reported in literature. The power produced by the reported piezoelectric AEHs ranges from 0.68 pW to 30 mW; however, the power generation of the developed electromagnetic AEHs is in the range of 1.5–1.96 mW. The overall size of most of the developed piezoelectric and electromagnetic AEHs are quite comparable and in millimeter scale. The resonant frequencies of electromagnetic AEHs are on the lower side (143–470 Hz), than that of piezoelectric AEHs (146 Hz–16.7 kHz).

Electromagnetic Bridge Energy Harvester Utilizing Bridge’s Vibrations and Ambient Wind for Wireless Sensor Node Application

“…Furthermore, due to the rapid developments in low power sensors, microcontrollers, conditioning circuits [6], power management circuits [7], and transmission module and because of efficient wireless sensor networks [8], the power requirement of WSNs is on a sharp decline. The energy harvesting technique [9][10][11][12][13] that is developed two decades ago has the tendency and capability to power these low power WSNs [14]. The energies, those are present in bridge's environment and can be taken into the account for energy harvesting, are vibration (vehicle-induced vibrations), acoustic (vehicle noise), wind (naturally blowing wind and air surges produced due to vehicle motion), and solar.…”

Bulk PZT Cantilever Based MEMS Acoustic Transducer for Cochlear Implant Applications

“…Maximum rectified DC output power was 16.25 μW with an open circuit voltage of 2.47 VDC. Among other MEMS acoustic energy harvesters in the literature, reported transducer has the highest power density (1.5 × 10 −3 W/cm 3 ) to our knowledge [6]. …”

An improved design of Helmholtz resonator for acoustic energy harvesting devices

“…In the last few years, with the rapid developments in microscale sensors, microelectronics, ultra large scale of integration (ULSI) and wireless communication networks, wireless sensor nodes (WSNs) appeared as one of the broadly used systems to sense and monitor [1]. The architecture of WSNs is shown in Fig.…”