Design Optimization of Piezoelectric Energy Harvesting Cantilever for Medical Devices

Energy harvesting from the human body is considered as an effective solution for powering biomedical systems. In particular, the piezoelectric energy recovery from mechanical vibrations of the human body represents the most promising solution. The harvested power depends on several factors such as the geometry, the size and materials used for the piezoelectric cantilever. In addition, the reduction and the change of the design of the piezoelectric system constitute a process for increasing the output power. In the present paper, the conventional rectangular shape of the piezoelectric energy harvester is studied and different shapes of cantilever are investigated. We introduced thus a triangular and a new shaped cantilever which permits the enhancement of the scavenged power for low frequencies. In addition, simulations result of various structures are compared and performed by employing finite element method (FEM). Simulations results show that the proposed form generates an electric power of 145 µW at resonant frequency of 8.5 Hz. This novel shape provides more efficient performance compared to other designs

A dual-band case-printed planar inverted-F antenna design with independent resonance control for wearable short range telemetric systems

In this article, a novel 3D meandered planar inverted-F antenna (PIFA) is proposed for dual band application targeting Wireless Body Area Network (WBAN). The proposed antenna is printed on the casing of a 3D-base-station model having a size of 88 × 95 × 10.2 mm3. The proposed PIFA covers two bands including medical implant communication service (MICS) (402-405 MHz), as well as the industrial, scientific, and medical (ISM) (2.4-2.48 GHz) bands. Each of the two bands can be controlled independently. The 3D configuration contains two linked meandered resonators to downsize the structure. Due to its conformal shape, omnidirectional radiation pattern, and low-profile nature, the proposed PIFA is a potential candidate for targeting the WBAN applications. The proposed antenna, covering the MICS and ISM bands, works with an optimally matching (VSWR<2) at the aforementioned bands. The design concept was validated by fabricating the antenna prototype and measuring its characteristics