Electric Field Imaging System

sensors
Electric Field Imaging System (LAR-TOPS-116)
Low-cost, noncontact imaging through electrical properties
Overview
NASA Langley Research Center's Electric Field Imaging (EFI) system is the only noncontact method capable of quantitatively measuring the magnitude and direction of electrostatic fields in near- and far-field applications. Based on low-cost, commercially available components, the EFI system uses measurement of very low-current, human-safe electric fields to construct a three-dimensional image of objects and people based on their dielectric properties. This platform technology, originally developed for measurement of the efficacy of electrical shielding around cables, could be optimized for a variety of applications, including medical imaging, security and detection, weather and natural disaster prediction, and nondestructive evaluation of composites and insulators. The EFI system has the potential to offer a lower-cost, portable, and safer alternative to the imaging systems currently used in these applications.

The Technology
The EFI imaging platform consists of a sensor array, processing equipment, and an output device. By registering voltage differences at multiple points within the sensor array, the EFI system can calculate the electrical potential at points removed from the sensor. Using techniques similar to computed tomography, the electrical potential data can be assembled into a three-dimension map of the magnitude and direction of electric fields. Since objects interact with electric fields differently based on their shape and dielectric properties, this electric field data can then be used to understand shape, internal structure, and dielectric properties (e.g., impedance, resistance) of objects in three dimensions. The EFI sensor can be used on its own to see electric fields or image electric fieldemitting objects near the sensor (e.g., to evaluate leakage from poorly shielded wires or casings). For evaluation of objects that do not produce an electric field, NASA has developed generator that emits a low-current, human-safe electrostatic field for snapshot evaluation of objects. Additionally, an alternative EFI system optimized to evaluate electric fields at significant distances (greater than 1 mile) is being developed for weather-related applications.
FIGURE 1 - Photograph of damaged
hybrid composite
Benefits
  • Enables noncontact, quantitative measurement of electrical or triboelectric properties and characterization of electric charges responsible for electrostatic discharge (ESD)
  • Can be optimized for localized or remote applications
  • Shows potential for highresolution imaging (tens of microns or better resolution for centimeter-scale to millimeter-scale objects)
  • Displays potential for near-real- time imaging with GHz data sampling rates
  • Does not require exposure to radiation, magnetic fields, heat, or light
  • Demonstrates potential for low-cost, portable construction
  • Can distinguish between nonconductive materials with high precision (potential capability to detect 0.01% change in dielectric properties between measurements)
  • Has easy-to-use, pointand- scan workflow design

Applications
  • Medical - remote, noncontact respiratory and vascular system monitoring, brain imaging, cancer detection, cardiac polarization wave imaging
  • Nondestructive evaluation - flaw detection in composites, evaluation of electrical properties of insulators, electrical shielding evaluation
  • Security - baggage and personnel screening, personnel detection, intrusion detection
  • Crime scene - forensic evaluation for history of events, what was touched with or without gloves, where people walked
  • Meteorology - lightning strike detection or prediction, guidance for lightning protection designs
Technology Details

sensors
LAR-TOPS-116
LAR-16565-1 LAR-18204-1 LAR-18396-1 LAR-18897-1 LAR-18666-1 LAR-19005-1 LAR-19007-1 LAR-18897-1-CON LAR-19007-2
Similar Results

Solid State Ephemeral Sensor, ergFET
Solid State Sensor for Detection and Characterization of Electric Fields
This equilibrium-reversing-gate field effect transistor (ergFET) deploys an electrode near the gate of the transistor to control and reverse leakage currents which are typical in transistors and can lead to measurement errors. It can be built into an array to enable higher resolution imaging and is a solid state device free of moving parts. This enables portable and hand held sensor designs.
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The invention uses the superconducting "proximity effect" and/or the "inverse proximity effect" to form a spatially varying order parameter. When designed to expel magnetic flux from a region of space, the proximity effect(s) are used in concert to make the superconducting order parameter strongly superconducting in the center and more weakly superconducting toward the perimeter. The shield is then passively cooled through the superconducting transition temperature. The superconductivity first nucleates in the center of the shielding body and expels the field from that small central region by the Meissner effect. As the sample is further cooled the region of superconducting order grows, and as it grows it sweeps the magnetic flux lines outward.
Security system keypad, engine inspection, robotic assembly line
Wireless Electrical Devices Using Floating Electrodes
The technology presents a fundamental change in the way electrical devices are designed, using an open circuit in conjunction with a floating electrode, or an electrically conductive object not connected to anything by wires, and powered through a wireless device. This system uses inductor-capacitor thin-film open circuit technology. It consists of a uniquely designed, electrically conductive geometric pattern that stores energy in both electric and magnetic fields, along with a floating electrode in proximity to the open circuit. When wirelessly pulsed from the handheld data acquisition system (U.S. Patent Number 7,159,774, Magnetic Field Response Measurement Acquisition System), the system becomes electrically active and develops a capacitance between the two circuit surfaces. The result is a device that acts as a parallel plate capacitor without electrical connections.
aircraft in front of lightning storm
Smart Skin for Composite Aircraft
When a lightning leader propagates through the atmosphere in the vicinity of an aircraft, the lightning electromagnetic emissions generated from the moving electrical charge will radiate the aircraft surface before the actual strike to the aircraft can occur. As the lightning leader propagates closer to the aircraft, the radiated emissions at the aircraft will grow stronger. By design, the frequency bandwidth of the lightning radiated is in the range for SansEC resonance. Hence the SansEC coil will be passively powered by the external oscillating magnetic field of the lightning radiated emission. The coil will resonate and generate its own oscillating magnetic and electric fields. These fields generate so-called Lorentz forces that influence the direction and momentum of the lightning attachment and thereby deflect/spread where the strike entry and exit points/damage occurs on the aircraft.
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