Infrared antennas with reconfigurable characteristics offer several advantages in the medical, military, telecommunication and energy harvesting areas, while their design and implementation is a particularly challenging task for the researchers. This paper proposes a pixel antenna, designed for mid-infrared frequencies with a bandwidth more than 25 THz, consisting of 3 × 3 square metallic planar patches. Bolometer-based switches are placed between the adjacent pixels in order to obtain the adaptable characteristics, optimized for the incoming infrared radiation. The incident wave from a certain direction will heat up the bolometers. Consequently, the conductivity of these bolometers (PTC) will be decreased, and as a result they can be considered to turn to OFF state. The simulation results suggest that the proposed structure can steer the antenna pattern toward the direction of the incident radiation in an adaptable manner, thereby considerably increasing the antenna gain. The gain of the antenna can be increased up to 2 dB with respect to the reference one, which makes it a promising structure for various applications.
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http://dx.doi.org/10.3390/s22103680 | DOI Listing |
Nano Lett
January 2025
Second Physics Institute, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Conducting polymers have emerged as promising active materials for metasurfaces due to their electrically tunable states and large refractive index modulation. However, existing approaches are often limited to infrared operation or single-polymer systems, restricting their versatility. In this Letter, we present organic metasurfaces featuring dual conducting polymers, polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT), to achieve contrasting dynamic optical responses at visible frequencies.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
We report a nonlinear terahertz (THz) detection device based on a metallic bull's-eye plasmonic antenna. The antenna, fabricated with femtosecond laser direct writing and deposited on a nonlinear gallium phosphide (GaP) crystal, focuses incoming THz waveforms within the sub-wavelength bull's eye region to locally enhance the THz field. Additionally, the plasmonic structure minimizes diffraction effects allowing a relatively long interaction length between the transmitted THz field and the co-propagating near-infrared gating pulse used in an electro-optic sampling configuration.
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January 2025
Applied BioSciences, Macquarie University, NSW, 2109, Sydney, Australia.
Male tephritid fruit flies typically emit pheromones from rectal glands to attract mates. Consistent with this, virgin females of the cucumber fruit fly, Zeugodacus cucumis (French), were found to be attracted to volatiles emitted by crushed male rectal glands in Y-tube olfactometer bioassays. Electrophysiological studies identified several male rectal gland compounds that triggered responses in female antennae.
View Article and Find Full Text PDFComp Biochem Physiol Part D Genomics Proteomics
December 2024
Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China; Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China. Electronic address:
Uridine diphosphate-glycosyltransferases (UGTs) are responsible for glycosylation by combining various small lipophilic molecules with sugars to produce water-soluble glycosides, which are crucial for the metabolism of plant secondary metabolites and detoxification in insects. This study presents a genome-wide analysis of the UGT gene family in the brown planthopper, Nilaparvata lugens, a destructive insect pest of rice in Asia. Based on the similarity to UGT homologs from other organisms, 20 putative NlUGT genes were identified in N.
View Article and Find Full Text PDFProtoplasma
January 2025
Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
Insect antennae play a crucial role in communication, acting as receptors for both chemical and physical cues. This sensory reception is facilitated by specialized cuticular structures known as sensilla, which exhibit diverse morphologies and functions. In ants, caste polymorphism and sexual dimorphism manifest in antennal structure.
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