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At least 109 records · Page 6

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DOE OSTI2021

Flexible Fabric-Based IDC Sensors for Conformal Curved Surface Applications

Interdigital capacitor (IDC) sensors are attractive in-situ sensors that can be used to measure permittivity variations in materials. Such sensors could be powerful enablers for cable insulation aging detection. Since insulation aging is correlated with a change in its material permittivity an IDC can measure that change via its measured capacitance. A new thin, flexible fabric-based IDC sensor is introduced for application on conformal curved surfaces such as an electrical cable surface. A multielectrode IDC and its backplane were fabricated using conductive copper polyester taffeta fabrics that were adhesively bonded to nonconductive polyester fabric. The sensor because of its soft flexible structure eliminates the problem of sensor conductor damage which is common for printed circuit board (PCB) type sensors when conformed to the surface of a cable. It also significantly reduces the airgap between the electrodes and the surface that they must contact in order to measure the capacitance. Airgap reduction and consistency are important in order to accurately predict permittivity variations in cable insulation material due to aging. Both PCB-based sensors and the new fabric-based sensors were built and tested on unaged cables and cables that underwent accelerated aging. Results demonstrate the proposed advantages of the novel fabric-based IDC sensor.

interdigital capacitor sensor, IDC, NDE, PCB senso↗

DOE OSTI2019

Simulation and Experimental Results of Interdigital Capacitor (IDC) Sensors to Monitor Insulation Degradation of Cables

The efficacy of using interdigital capacitor (IDC) sensors to monitor cable insulation aging was studied through electromagnetic simulations and experimental measurements. Simulation results on both planar and conformal dielectric materials indicated that IDCs on thin substrates and with conducting backplanes provide superior performance in terms of higher capacitance. An airgap study showed that even a very small airgap between the sensor and the cable’s insulation results in significant reduction in capacitance; therefore, airgaps should be minimized. Finally, cables that underwent accelerated aging exposure in an oven were tested using fabricated IDC sensors. Measurement results showed a 12.5% increase in capacitance when the IDC was pressed against the insulation versus a 91.3% increase in capacitance when the IDC was pressed against the jackets of the cables for cable specimens ranging from unaged to aged 35 days.

Cable NDE, Interdigital Capacitance↗

DOE OSTI2019

Defeat system for vehicle attached improvised explosive devices

An explosive device detection and expulsion system broadly comprising a detection subsystem for sensing an IED attached to a vehicle and an expulsion subsystem for expelling the IED from the vehicle. The detection subsystem includes a sensor for detecting an IED via an electromagnetic field change or capacitance change, vibrations, and/or heat, and a controller for activating the expulsion subsystem upon receiving a detection signal from the sensor. The expulsion subsystem includes a deployable panel configured to be attached to the vehicle and a deployable mechanism for shifting the deployable panel from an undeployed state to a deployed state so as to expel the IED from the vehicle.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2021

Defeat system for vehicle attached improvised explosive devices

Hower, Brent↗

DOE OSTI2019

In Situ Monitoring of Direct Ink Write Process Using Electromagnetic Resonant Coupling

Additive manufacturing (AM) of multi-material objects enables the design of complex 3D architectures such as printed electronics and devices. The ability to detect the composition of multi-material printed inks in real time is an emerging need for a wide range of manufacturing applications. This study demonstrates the feasibility of using an in situ sensor to locally measure the composition of inks as they are being printed to facilitate greater control over the resulting properties and functionality of printed materials. Dielectric properties of microscale embedded metal particles in a dielectric matrix are measured and characterized as a function of particle size, shape, volume percentage and frequency. Results show that particle shape has a much greater influence on impedance measurements than the particle size. Measurements are found to agree with calculations based on an anisotropic Maxwell-Garnett dielectric function model. The resulting data can be used to generate a calibration curve correlating metal loading with impedance or capacitance and thus applied as an in situ sensor for compositional measurements during extrusion-based AM.

36 MATERIALS SCIENCE↗

DOE OSTI2016

PC board mount corrosion sensitive sensor

The present invention relates to surface mount structures including a capacitive element or a resistive element, where the element has a property that is responsive to an environmental condition. In particular examples, the structure can be optionally coupled to a printed circuit board. Other apparatuses, surface mountable structures, and methods of use are described herein.

42 ENGINEERING↗

DOE OSTI2021

A stretchable and strain-unperturbed pressure sensor for motion interference–free tactile monitoring on skins

A stretchable pressure sensor is a necessary tool for perceiving physical interactions that take place on soft/deformable skins present in human bodies, prosthetic limbs, or soft robots. However, all existing types of stretchable pressure sensors have an inherent limitation, which is the interference of stretching with pressure sensing accuracy. Here, we present a design for a highly stretchable and highly sensitive pressure sensor that can provide unaltered sensing performance under stretching, which is realized through the synergistic creations of an ionic capacitive sensing mechanism and a mechanically hierarchical microstructure. Via this optimized structure, our sensor exhibits 98% strain insensitivity up to 50% strain and a low pressure detection limit of 0.2 Pa. With the capability to provide all the desired characteristics for quantitative pressure sensing on a deformable surface, this sensor has been used to realize the accurate sensation of physical interactions on human or soft robotic skin.

47 OTHER INSTRUMENTATION↗

DOE OSTI2019

Fast timing with induced current detectors

Vertically integrated (3D) combinations of sensors and electronics offer the ability to fabricate small, fine pitch pixels with very small total capacitance monolithically integrated with complex circuitry. The small capacitance, enabled by the fine pixel pitch and low interconnect capacitance available in 3D hybrid bonding, provides excellent signal/noise with moderate power. This combination enables fabrication of integrated sensors and electronics with both excellent position and time resolution. We describe the capabilities of such a system and the limitations imposed by geometry and power. Furthermore, we illustrate how a similar geometry can be used to provide very fast timing of x-ray arrival in a thick sensor by utilizing the transient induced current in a field of pixels.

3D integration↗

DOE OSTI2022

Integration and Packaging

Vertically integrated (3D) combinations of sensors and electronics provide the ability to fabricate small, fine pitch pixels with very small total capacitance monolithically integrated with complex circuitry. The small capacitance, enabled by the fine pixel pitch and low interconnect capacitance available in 3D hybrid bonding, provides excellent signal/noise with moderate power. This combination enables fabrication of integrated sensors and electronics with both excellent position and time resolution. In this white paper a discussion will be presented on 3D integration advantages, ongoing projects and prospects in high energy physics and beyond.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2024

Characterizing novel Indium Phosphide pad detectors with focused X-ray beams and laboratory tests

Future tracking systems in High Energy Physics experiments will require large instrumented areas with low radiation length. Crystalline silicon sensors have been used in tracking systems for decades, but are difficult to manufacture and costly to produce for large areas. We are exploring alternative sensor materials that are amenable to fast fabrication techniques used for thin film devices. Indium Phosphide pad sensors were fabricated at Argonne National Lab using commercially available InP:Fe 2-inch mono-crystal substrates. Current-voltage and capacitance-voltage characterizations were performed to study the basic operating characteristics of a group of sensors. Micro-focused X-ray beams at Canadian Light Source and Diamond Light Source were used to study the response to ionizing radiation, and characterize the uniformity of the response for several devices. Electrical test results showed a high degree of performance uniformity between the 48 tested devices. X-ray test beam results showed good performance uniformity within tested devices after accounting for spatially-local defects and edge fields. As a result, this motivates further studies into thin film devices for future tracking detectors.

47 OTHER INSTRUMENTATION↗

DOE OSTI2023

A Threshold Helium Leakage Detection Switch with Ultra Low Power Operation

Detecting helium leakage is important in many applications, such as in dry cask nuclear waste storage systems. This work develops a helium detection system based on the relative permittivity (dielectric constant) difference between air and helium. This difference changes the status of an electrostatic microelectromechanical system (MEMS) switch. The switch is a capacitive-based device and requires a very negligible amount of power. Exciting the switch’s electrical resonance enhances the MEMS switch sensitivity to detect low helium concentration. This work simulates two different MEMS switch configurations: a cantilever-based MEMS modeled as a single-degree-freedom model and a clamped-clamped beam MEMS molded using the COMSOL Multiphysics finite-element software. While both configurations demonstrate the switch’s simple operation concept, the clamped-clamped beam was selected for detailed parametric characterization due to its comprehensive modeling approach. The beam detects at least 5% helium concentration levels when excited at 3.8 MHz, near electrical resonance. The switch performance decreases at lower excitation frequencies or increases the circuit resistance. The MEMS sensor detection level was relatively immune to beam thickness and parasitic capacitance changes. However, higher parasitic capacitance increases the switch’s susceptibility to errors, fluctuations, and uncertainties.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2018

Testbeam results of irradiated ams H18 HV-CMOS pixel sensor prototypes

HV-CMOS pixel sensors are a promising option for the tracker upgrade of the ATLAS experiment at the LHC, as well as for other future tracking applications in which large areas are to be instrumented with radiation-tolerant silicon pixel sensors. We present results of testbeam characterisations of the 4 th generation of Capacitively Coupled Pixel Detectors (CCPDv4) produced with the ams H18 HV-CMOS process that have been irradiated with different particles (reactor neutrons and 18 MeV protons) to fluences between 1×10 14 and 5×10 15 1–MeV– n eq . The sensors were glued to ATLAS FE-I4 pixel readout chips and measured at the CERN SPS H8 beamline using the FE-I4 beam telescope. Results for all fluences are very encouraging with all hit efficiencies being better than 97% for bias voltages of 85 V. The sample irradiated to a fluence of 1×10 15 neq—a relevant value for a large volume of the upgraded tracker—exhibited 99.7% average hit efficiency. Furthermore, the results give strong evidence for the radiation tolerance of HV-CMOS sensors and their suitability as sensors for the experimental HL-LHC upgrades and future large-area silicon-based tracking detectors in high-radiation environments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2019

Adaptive Electrical Capacitance Volume Tomography for Measuring High Temperature Solids Circulation Rate in Circulating Fluidized Bed (CFB) Combustors

Explore the source record for details and available documents.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2021

Microfabricated ion trap chip with in situ radio-frequency sensing

A radio-frequency (RF) surface ion trap chip includes an RF electrode and an integrated capacitive voltage divider in which an intermediate voltage node is capacitively connected between the RF electrode and a ground. A sensor output trace is connected to the intermediate voltage node.

Maunz, Peter Lukas Wilhelm↗

DOE OSTI2016

Mutual capacitance of liquid conductors in deformable tactile sensing arrays

Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2013

Epidermal Impedance Sensing Sheets for Precision Hydration Assessment and Spatial Mapping

This paper presents a class of hydration monitor that uses ultrathin, stretchable sheets with arrays of embedded impedance sensors for precise measurement and spatially multiplexed mapping. The devices contain miniaturized capacitive electrodes arranged in a matrix format, capable of integration with skin in a conformal, intimate manner due to the overall skin-like physical properties. These “epidermal” systems noninvasively quantify regional variations in skin hydration, at uniform or variable skin depths. Experimental results demonstrate that the devices possess excellent uniformity, with favorable precision and accuracy. Theoretical models capture the underlying physics of the measurement and enable quantitative interpretation of the experimental results. Furthermore, these devices are appealing for applications ranging from skin care and dermatology, to cosmetology and health/wellness monitoring, with the additional potential for combined use with other classes of sensors for comprehensive, quantitative physiological assessment via the skin.

42 ENGINEERING↗

DOE OSTI2019

Performance of CMOS pixel sensor prototypes in ams H35 and aH18 technology for the ATLAS ITk upgrade

Pixel sensors based on commercial high-voltage CMOS processes are an exciting technology that is considered as an option for the outer layer of the ATLAS inner tracker upgrade at the High Luminosity LHC. Here, charged particles are detected using deep n-wells as sensor diodes with the depleted region extending into the silicon bulk. Both analog and digital readout electronics can be added to achieve different levels of integration up to a fully monolithic sensor. Small scale prototypes using the ams CMOS technology have previously demonstrated that it can achieve the required radiation tolerance of 10(15) n(eq)/cm(2) and detection efficiencies above 99.5%. Recently, large area prototypes, comparable in size to a full sensor, have been produced that include most features required towards a final design: the H35demo prototype produced in ams H35 technology that supports both external and integrated readout and the monolithic ATLASPix1 pre-production design produced in ams aH18 technology. Both chips are based on large fill-factor pixel designs, but differ in readout structure. Performance results for H35DEMO with capacitively-coupled external readout and first results for the monolithic ATLASPix1 are shown.

ATLAS ITk upgrade↗

DOE OSTI2013

Real-time control of electron density in a capacitively coupled plasma

Reactive ion etching (RIE) is sensitive to changes in chamber conditions, such as wall seasoning, which have a deleterious effect on process reproducibility. The application of real time, closed loop control to RIE may reduce this sensitivity and facilitate production with tighter tolerances. The real-time, closed loop control of plasma density with RF power in a capacitively coupled argon plasma using a hairpin resonance probe as a sensor is described. Elementary control analysis shows that an integral controller provides stable and effective set point tracking and disturbance attenuation. The trade off between performance and robustness may be quantified in terms of one parameter, namely the position of the closed loop pole. Experimental results are presented, which are consistent with the theoretical analysis.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗