Electric Field Imaging System

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.

The SansEC sensor system consists of multiple pairs of inductor-capacitor sensors with no electrical connections, which are placed throughout the material being monitored for damage. The sensors are embedded in or placed directly onto the surface of the material. Strains and breaks are detected by changes in resonant frequency read by the accompanying magnetic field data acquisition system. When pulsed by a sequence of magnetic field harmonics from the acquisition system, the sensors become electrically active and emit a wireless response. The magnetic field response attributes of frequency, amplitude, and bandwidth of the inductor correspond to the physical property states measured by the sensor. The received response is correlated to calibration data to determine the physical property measurement. Because each sensor pair has its own frequency response, when damage occurs to that circuit the frequency response changes. This change identifies the damage location within the material. A unique feature achieved by eliminating electrical connections is that damage to a single point will not prevent the sensor from being powered or interrogated. If a sensor is broken, two concentric inductively coupled sensors are created, thus identifying tamper or damage location.

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.

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.

A time-varying electrical field E, having a root-mean-square intensity of 2rms, with a non-zero gradient in a direction transverse to the liquid or fluid flow direction, is produced by a nanostructure electrode array with a very high magnitude gradient near exposed electrode tips. A dielectrophoretic force causes the selected particles to accumulate near the electrode tips, if the medium and selected particles have substantially different dielectric constants. An insulating material surrounds most of the nanostructure electrodes, and a region of the insulating material surface is functionalized to promote attachment of the selected particle species to the surface. An electrical property value Z(meas) is measured at the functionalized surface, and is compared with a reference value Z(ref) to determine if the selected species particles are attached to the functionalized surface. An advantage of this innovation is that an array of nanostructure electrodes can provide an electric field intensity gradient that is one or more orders of magnitude greater than the corresponding gradient provided by a conventional microelectrode arrangement. As a result of the high magnitude field intensity gradients, a nanostructure concentrator can trap particles from high-speed microfluidic flows. This is critical for applications where the entire analysis must be performed in a few minutes.