Broadband S-parameter measurements of Parylene C microwave microfluidic devices from 100 MHz - 110 GHz. The Parylene C devices consisted of 400 nm platinum coplanar waveguides (CPW) (50 um center conductor, 5 um gaps, 200 um ground planes) deposited on fused silica with 6.5 um of Parylene C on top, capped with a PDMS microfluidic layer aligned over the CPWs. The dimensions of the PDMS microfluidic channels were approximately 210 um wide by 100 um deep. The total CPW line length was 10.000 mm and the channel length was 4.160 mm, where the channel was aligned over the center of the CPW. We measured the S-parameters of Parylene C devices filled with three different fluid conditions at different intervals over a 2 month period: H2O at 20 degrees Celsius, 1xPBS (phosphate-buffered saline) at 20 degrees Celsius, and 1xPBS at 37 degrees Celsius. We obtained measurements of both the fluid-filled and empty channel at each measurement day. We measured broadband S-parameters with a vector network analyzer and extender heads at a source power of -17 dBm on a temperature-controlled probe station. The S-parameters were calibrated to the probe tips with measurements of a gold reference chip in combination with multiline TRL in the NIST Microwave Uncertainty Framework. The differences in S-parameters from day 0 were plotted over time to observe changes in the dielectric properties of the Parylene C device during soaking.

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.

Included here are figures and other relevant data from the paper "Measurements of nonlinear polarization dynamics in the tens of GHz" to be published in Physical Review Applied.Abstract: Frequency-dependent linear permittivity measurements are commonplace in the literature, providing key insights into the structure of dielectric materials. These measurements describe a material's dynamic response to a small applied electric field. In contrast, nonlinear dielectric materials are widely used for their responses to large applied fields, including switching in ferroelectric materials, and field-tuning of the permittivity in paraelectric materials. These behaviors are described by nonlinear permittivity. Nonlinear permittivity measurements are fraught with technical challenges because of the complex electrical coupling between a sample and its environment. Here, we describe a technique for measuring the complex nonlinear permittivity that circumvents many of the difficulties associated with other approaches. We validate this technique by measuring a the nonlinear permittivity of a tunable Ba0.5Sr0.5TiO thin film up to 40 GHz and comparing our results with a phenomenological model. These measurements provide insight into the dynamics of nonlinear dielectric materials down to picosecond timescales.

Included here are figures and other relevant data from the paper "Measurements of nonlinear polarization dynamics in the tens of GHz" to be published in Physical Review Applied.Abstract: Frequency-dependent linear permittivity measurements are commonplace in the literature, providing key insights into the structure of dielectric materials. These measurements describe a material's dynamic response to a small applied electric field. In contrast, nonlinear dielectric materials are widely used for their responses to large applied fields, including switching in ferroelectric materials, and field-tuning of the permittivity in paraelectric materials. These behaviors are described by nonlinear permittivity. Nonlinear permittivity measurements are fraught with technical challenges because of the complex electrical coupling between a sample and its environment. Here, we describe a technique for measuring the complex nonlinear permittivity that circumvents many of the difficulties associated with other approaches. We validate this technique by measuring a the nonlinear permittivity of a tunable Ba0.5Sr0.5TiO thin film up to 40 GHz and comparing our results with a phenomenological model. These measurements provide insight into the dynamics of nonlinear dielectric materials down to picosecond timescales.

This data set consists of both measured and simulated optical intensities scattered off periodic line arrays, with simulations based upon an average geometric model for these lines. These data were generated in order to determine the average feature sizes based on optical scattering, which is an inverse problem for which solutions to the forward problem are calculated using electromagnetic simulations after a parameterization of the feature geometry. Here, the array of features measured and modeled is periodic in one-dimension (i.e., a line grating) with a nominal line width of 100 nm placed at 300 nm intervals, or pitch = 300 nm; the short-hand label for the features is "L100P300." The entirety of the modeled data is included, over two thousand simulations that are indexed using a top, middle, and bottom linewidth as floating parameters. Two subsets of these data, featuring differing sampling strategies, are also provided. This data set also contains angle-resolved optical measurements with uncertainties for nine arrays which differ in their dimensions due to lithographic variations using a focus/exposure matrix, as identified in a previous publication (https://doi.org/10.1117/12.777131). We have previously reported line widths determined from these measurements based upon non-linear regression to compare theory to experiment. Machine learning approaches are to be fostered for solving such inverse problems. Data are formatted for direct use in "Model-Based Optical Metrology in R: MoR" software which is also available from data.nist.gov. (https://doi.org/10.18434/T4/1426859). Note: Certain commercial materials are identified in this dataset in order to specify the experimental procedure adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials are necessarily the best available for the purpose.

Supplemental data for "Comparison of measured and simulated spin-wave mode spectra of magnetic nanostructures" by H. T. Nembach, R.D. McMichael, M.L. Schneider, J.M. Shaw, T.J. Silva.1) Experimental spectra of approximately elliptical, 100 nm or 200 nm elliptical magnetic structures. 2) SEM images of the magnetic structures 3) Scripts and data used in micromagnetic modeling and simulated measurements of the structures. Experiment: In this work, we prepared two sets of Ni80Fe20 elliptical nanomagnets with nominal long axes lengths (short axes lengths) of 240 nm (200 nm) and 120 nm (100 nm): Thin-film layers of 3 nm Ta/10 nm Ni80Fe20/5 nm Si3N4 were dc-magnetron sputtered onto a sapphire substrate before a 15-nm diamond-like carbon (DLC) layer was deposited via ion-beam deposition in a separate vacuum chamber. The spin wave mode spectra of the magnetization dynamics were measured with a heterodyne magneto-optical microwave microscope (H-MOMM) Simulations: We carried out micromagnetic simulations using the Object Oriented MicroMagnetic Framework (OommF). To determine the shape for modeled nanomagnets, greyscale SEM images of the nanomagnets were converted into binary images using a thresholding algorithm. The original SEM images were given a Gaussian blur over 1.4 nm (3 pixels), rescaled by 25 % and given a secondary blur over 3.8 nm. A threshold value was determined using Otsu's method. The simulated spectra were extracted from impulse response calculations made at an array of applied field values in the experimental range. The modeling also provides the spatial profile of the spin wave modes. The bulk of the data is associated with the micromagnetic modeling. Files include OommF input '.mif' scripts, sample masks, modeling output and python scripts for analysis and plotting, and the resulting figures.

The data presented in this data file is a product of journal publication. The dataset contains air velocity of testing chambers, and convective mass transfer coefficient, diffusion coefficient, and material / air partition coefficient of formaldehyde with different building materials. Portions of this dataset are inaccessible because: CFD data was generated and stored by North Carolina State University because the files are too big and need specific software to open. They can be accessed through the following means: Please contact Jack Edwards at North Carolina State University. Format: CFD modeling data files. This dataset is associated with the following publication: Edwards, J., C. Huang, and X. Liu. Computational Fluid Dynamics Analysis of a Micro-scale Chamber for Measuring Organic Chemical Emission Parameters. JOURNAL OF HAZARDOUS MATERIALS. Elsevier Science Ltd, New York, NY, USA, 0, (2024).