Skip to main content
U.S. flag

An official website of the United States government

This site is currently in beta, and your feedback is helping shape its ongoing development.

Return to search results

Broadband Electromagnetic Properties of Engineered Flexible Absorber Materials

Published by National Institute of Standards and Technology | National Institute of Standards and Technology | Metadata Last Checked: August 02, 2025 | Last Modified: 2023-01-17 00:00:00
Figures and relevant data from the paper "Broadband Electromagnetic Properties of Engineered Flexible Absorber Materials" are found here . The paper was published on Advanced Materials Technologies in 2023. ABSTRACT: Flexible and stretchable materials have attracted significant interest for applications in wearable electronics and bioengineering fields. Recent developments also incorporate mounted and embedded microwave circuits, components, and systems with engineered flexible materials that operate over a broadband frequency range (~1 to 100 GHz). Here we demonstrate a simple, low-cost, flip-chip technique where flexible materials are placed on top of coplanar waveguide (CPW) transmission lines for material property measurement. We apply on-wafer error correction and de-embedding techniques to determine broadband electromagnetic properties of the material-loaded transmission line segments. Finite-element simulations of material-loaded devices were employed along with the broadband measurements to estimate the electromagnetic material properties. To demonstrate this technique, we fabricated flexible polydimethylsiloxane (PDMS) composites with varying concentrations of Barium Hexaferrite (BaM) nanoparticles for potential applications in electromagnetic shielding and quantified the complex permittivity and permeability of the composites up to 110 GHz using our broadband scattering-parameter measurements. We fit the frequency-dependent permeability to models describing the ferromagnetic resonance of barium hexaferrite (BaM) nanoparticles in PDMS and estimated the constituent nanoparticle properties using the Maxwell-Garnett mixing model. This study paves way to exploit a wide range of engineered materials in flexible, wearable, and biomedical electronics applications and presents a convenient methodology to extract important broadband electromagnetic properties for applications such as electromagnetic shielding.

Resources

16 resources available

  • Calculated and extracted real part of effective permeability for samples

    TEXT/CSV
  • Calculated and extracted imaginary part of effective permeability for samples

    TEXT/CSV
  • Frequency dependence of the capacitance per unit length

    TEXT/CSV
  • Frequency dependence of the conductance per unit length (LDUT)

    TEXT/CSV
  • Calculated imaginary effective permittivity (εeff) vs. frequency

    TEXT/CSV
  • Figure 1: Reference chip, air and composite loaded test chips subject to measurement.

    IMAGE/PNG
  • Calculated real effective permittivity (εeff) vs. frequency

    TEXT/CSV
  • Figure 4: Material loaded transmission lines and de-embedding in test wafer

    IMAGE/PNG
  • Figure 2: Frequency dependent R, L, C, G (per unit length) transmission line model that is used for simulations and calculations

    IMAGE/PNG
  • Differential substrate capacitance vs. substrate permittivity

    TEXT/CSV
  • Differential superstrate capacitance vs. superstrate permittivity

    TEXT/CSV
  • Differential inductance vs. superstrate permeability

    TEXT/CSV
  • Calculated and measured distributed circuit parameters - Inductance per unit length

    TEXT/CSV
  • Calculated and measured distributed circuit parameters - Resistance per unit length

    TEXT/CSV
  • Estimates for the free-space attenuation constant for engineered BaM-PDMS composites

    TEXT/CSV
  • Readme File for Figures with Description

    TEXT/PLAIN

data.gov

An official website of the GSA's Technology Transformation Services

Looking for U.S. government information and services?
Visit USA.gov