Metamaterial absorbers have been widely studied and continuously concerned owing to their excellent resonance features of ultra‐thin thickness, light‐weight, and high absorbance. Their applications, however, are typically restricted by the intrinsic dispersion of materials and strong resonant features of patterned arrays (mainly referring to narrow absorption bandwidth). It is, therefore essential to reassert the principles of building broadband metamaterial absorbers (BMAs). Herein, the research progress of BMAs from principles, design strategies, tunable properties to functional applications are comprehensively and deeply summarized. Physical principles behind broadband absorption are briefly discussed, typical design strategies in realizing broadband absorption are further emphasized, such as top‐down lithography, bottom‐up self‐assembly, and emerging 3D printing technology. Diversified active components choices, including optical response, temperature response, electrical response, magnetic response, mechanical response, and multi‐parameter responses, are reviewed in achieving dynamically tuned broadband absorption. Following this, the achievements of various interdisciplinary applications for BMAs in energy‐harvesting, photodetectors, radar‐IR dual stealth, bolometers, noise absorbing, imaging, and fabric wearable are summarized. Finally, the challenges and perspectives for future development of BMAs are discussed.

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

Optical metasurfaces with subwavelength thickness hold considerable promise for future advances in fundamental optics and novel optical applications due to their unprecedented ability to control the phase, amplitude, and polarization of transmitted, reflected, and diffracted light. Introducing active functionalities to optical metasurfaces is an essential step to the development of next-generation flat optical components and devices. During the last few years, many attempts have been made to develop tunable optical metasurfaces with dynamic control of optical properties (e.g., amplitude, phase, polarization, spatial/spectral/temporal responses) and early-stage device functions (e.g., beam steering, tunable focusing, tunable color filters/absorber, dynamic hologram, etc) based on a variety of novel active materials and tunable mechanisms. These recently-developed active metasurfaces show significant promise for practical applications, but significant challenges still remain. In this review, a comprehensive overview of recently-reported tunable metasurfaces is provided which focuses on the ten major tunable metasurface mechanisms. For each type of mechanism, the performance metrics on the reported tunable metasurface are outlined, and the capabilities/limitations of each mechanism and its potential for various photonic applications are compared and summarized. This review concludes with discussion of several prospective applications, emerging technologies, and research directions based on the use of tunable optical metasurfaces. We anticipate significant new advances when the tunable mechanisms are further developed in the coming years.

Active optical metasurfaces: comprehensive review on physics, mechanisms, and prospective applications

Insights to low electrical percolation thresholds of carbon-based polypropylene nanocomposites

Microwave absorption materials (MAMs) were originally developed for military purposes, but have since evolved into versatile materials with promising applications in modern technologies, including household use. Despite significant progress in bench-side research over the past decade, MAMs remain limited in their scope and have yet to be widely adopted. This review explores the history of MAMs from first-generation coatings to second-generation functional absorbers, identifies bottlenecks hindering their maturation. It also presents potential solutions such as exploring broader spatial scales, advanced characterization, introducing liquid media, utilizing novel toolbox (machine learning), and proximity of lab to end-user. Additionally, it meticulously presents compelling applications of MAMs in medicine, mechanics, energy, optics, and sensing, which go beyond absorption efficiency, along with their current development status and prospects. This interdisciplinary research direction differs from previous research which primarily focused on meeting traditional requirements (i. e., thin, lightweight, wide, and strong), and can be defined as the next generation of smart absorbers. Ultimately, the effective utilization of ubiquitous electromagnetic waves, aided by third-generation MAMs, should be better aligned with future expectations. This article is protected by copyright. All rights reserved.

Advancements in Microwave Absorption Motivated by Interdisciplinary Research.

In this paper, we present a simple design of six-band terahertz (THz) perfect metasurface absorber (PMSA) composed of a single circular-split-ring (CSR) structure placed over a ground-plane by a dielectric substrate. The average absorbance of 99.1% at six distinct frequencies can be obtained for the proposed PMSA under normal incident THz wave. The distribution characteristics of electric field reveal that the six absorption peaks of the proposed PMSA mainly originate from the combination of the higher-order localized surface plasmon (LSP) and propagating surface plasmon (PSP) resonance modes. Moreover, the influences of geometric parameters on the resonance absorption properties of PMSA were investigated numerically. Owing to its excellent properties, this design of the six-band PMSA may have potential applications in imaging, sensing and detection.

Simple design of a six-band terahertz perfect metasurface absorber based on a single resonator structure

In this letter, a swastika-shaped ultrabroadband metamaterials absorber is proposed. The designed absorber can be fabricated with the polylactic acid by 3-D printing, and packaged after filling with water. The absorber can achieve greater than 90% absorption in the frequency band of 9.3–49.0 GHz, with a relative bandwidth of 136%, which has been well demonstrated in the microwave experiment. Moreover, it also performs well at wide angles of incidence and the absorption efficiency has almost no obvious changes over the water temperature range of 0 °C–100 °C. The absorber proposed in this letter benefits from ultrawideband absorption, low cost and environment-friendly materials, it can be applied in the fields of electromagnetic (EM) stealth and EM energy harvesting.

3-D Printed Swastika-Shaped Ultrabroadband Water-Based Microwave Absorber

Multi-band metamaterial absorbers (MMAs) are widely used in detecting and sensing fields to achieve selective frequency detection. In this study, a triple-narrowband absorber based on a symmetrical dual-trident structure is numerically designed for high absorption and sensing applications in the terahertz region. Simulation results show that the maximum absorptivity of three distinctive narrow-band absorption peaks is up to 99.94% and any of the three resonance frequencies can be utilized for bio-sensing. According to bio-sensing detection, the proposed sensor can simultaneously detect the thickness and refractive index of an unknown layer by utilizing different frequency shifts of the three resonance absorption peaks. The deviation of RI and thickness is 0.075 and zero, respectively. Results show that such a simple designed absorber could provide a desirable promising for terahertz-wave absorption and sensing applications.

A multi-band absorber based on a dual-trident structure for sensing application

Metasurfaces, which are composed of two-dimensional arrays of subwavelength structures, can reshape the wavefront arbitrarily by introducing phase discontinuities with the entire 2π phase region. In this paper, we demonstrate a switchable metalens based on active tri-layer metasurfaces by hybridizing a phase-change material, vanadium dioxide (VO2). The reflection and transmission coefficients of the metasurface element and the focusing performance of the switchable metalens were studied and simulated. At room temperature (300 K), VO2 behaves as a semiconductor and our proposed metalens can reflect and converge the co-polarized terahertz wave with high efficiency, working as a reflective lens. When the temperature is up to around 400 K, the VO2 material is switched into metal phase and the proposed metalens is switched into its operating state as a transmission mode for the cross-polarized terahertz wave. By thermal stimulation or electrical bias, the switchable meta-devices proposed in this paper can be applied in the fields for imaging, communication, and power modulation.

A Switchable Metalens Based on Active Tri-Layer Metasurface

The demand for multi-functional soft actuators with simple fabrication and fast response to multiple stimuli is increasing in the field of smart devices. However, for existing actuators that respond to a single stimulus, it is difficult to meet the requirements of application diversity. Herein, a type of multi-stimulus responsive soft actuator based on the Nafion-Polypropylene-polydimethylsiloxane (PDMS)/Graphite multilayer membranes is proposed. Such actuators have an excellent reversible response to optical/thermal and humidity stimulation, which can reach a 224.56° bending angle in a relative humidity of 95% within 5 s and a maximum bending angle of 324.65° in 31 s when the platform temperature is 80 °C, and has a faster response (<0.5 s) to optical stimuli, as an asymmetric structure allows it to bend in both directions. Based on such an actuator, some applications like flexible grippers and switches to carry items or control circuits, bionic flytraps to capture and release “prey”, have also been developed and studied. These provide potential applications in the fields of soft sensors, artificial skin and flexible robots.

https://www.mdpi.com/2076-3417/10/5/1829/pdf

Smart Devices Based on the Soft Actuator with Nafion-Polypropylene-PDMS/Graphite Multilayer Structure

The fabrication of optical and magnetic responsive deforming multilayered film

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Yanjun Fu

Author Tools

Chat about Author