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This research introduces an innovative method for crafting adjustable one-dimensional photonic crystals by integrating a polyvinylidene fluoride (PVDF) piezoelectric layer into a ternary polymer structure. The incorporation of PVDF as a piezoelectric polymer in the photonic crystal allows for the simulation of an electric field sensitive photonic crystal. Two structures of the photonic crystal are examined, one with a defect layer and one without, while the impact of piezoelectric parameters on the transmission spectrum is scrutinized. The computational outcomes clearly demonstrate that the photonic band gap can be efficiently modified by applying an external electric field in the THz frequency. Incorporating a defect mode that is sensitive to electric field allows for the creation of a narrow bandpass region (∼ 5 GHz) within a bandgap. This narrow region has the capacity to be precisely modified through the application of an external electrical field. This distinctive design proposal provides a means to govern and modify the optical characteristics of the crystal, rendering it a promising candidate for diverse photonic applications. • The study presents a novel technique for creating adjustable one-dimensional photonic crystals using apolyvinylidene fluoride (PVDF) piezoelectric layer. • By integrating PVDF, the photonic crystal becomes sensitive to electric fields, enabling the simulation of responsive optical properties. • The research examines two photonic crystal structures—one with a defect layer and one without—to understand how piezoelectric parameters influence the transmission spectrum. • Computational results reveal that the photonic band gap can be effectively altered by applying an external electric field at THz frequencies. • A defect mode sensitive to electric fields is introduced, allowing for the creation of a narrow bandpass region (∼5 GHz) within the bandgap, which can be precisely adjusted with an external electrical field. [ABSTRACT FROM AUTHOR]

This paper presents an optimized AC–DC converter designed in 65 nm low power process technology. Two topologies of the AC–DC converter are designed, namely, Bias-Flip rectifier and Voltage Doubler. The design is part of a piezo electric energy harvesting system targeting wearable electronics. Voltage doubler and full-bridge rectifier are fabricated to support a start-up mechanism while the bias-flip rectifier supports higher efficiency for the normal operation mode. Using a piezo electric energy harvester mounted on a shaker and operated at 4.5 Hz, the maximum extracted power from the voltage doubler is measured as 79.8 nW at 0.21 g. In addition, the maximum extracted power from the full-bridge rectifier is measured as 22.2 nW. As such, voltage doubler is more efficient than full-bridge rectifier by 71%. The experiment uses MIDE V22BL piezo electric harvester with 25 Hz resonance frequency. However, the harvester was used at 4.5 Hz (human frequency) which degrade the energy extracted from the harvester. If another harvester was designed to tune to lower frequency, higher energy level can be extracted. Another contribution in this paper is to compare the on-chip voltage doubler to board level with discrete components. Our experimental results show 11% improvement in efficiency for the on-chip design compared to off-chip for the same input power. The combined bias-flip rectifier and voltage doubler support energy autonomous systems where no start-up power is needed. [ABSTRACT FROM AUTHOR]