Electrical biasing

FIG. 1 Schematic representation of the operation of the scanning polarization force microscope (SPFM). An electrically biased AFM tip is attracted toward the surface of any dielectric material. The polarization force depends on the local dielectric properties of the substrate. SPFM images are typically acquired with the tip scanning at a height of 100-300 A. (From Ref. 32.)... 

It has also been demonstrated that the sensing electrode can be maintained at a predetermined voltage of 1.0 V by electrically biasing (constant voltage source) the sensing electrode vs. a stable counter-reference, such as Pt/Hp, H+ or PbOp/PbSO, H+ (1, 2,3). With the former, the sensing electrode is electrically biased 1.0 V above the Pt/Hp,H+ potential (0.0 V) and with the latter 0.7 V below the PbOp/PbSOi, H+ potential (1.7 V). Both of these counter-reference electrodes exhibit good reversibility, but reliability and life are not adequate. 

The most convenient and reliable electrical biasing method for use with a hydrated SPE cell has been shown to be a three electrode potentiostatic circuit which maintains the sensing electrode at a predetermined potential vs. a stable reference (1 >3.>j0e The most reversible reference is a Pt/Hp, H+, static or dynamic. In practical instruments, however, good accuracy and convenience are achieved using a large surface area platinoid metal black/air (Op). All work reported in this study utilized the air reference which has a potential of approximately +1.05 V vs. a standard hydrogen electrode (SHE). For convenience, all potentials reported are vs. the SHE ... 

Dempsey, R.M. LaConti, A.B. Nolan, M.E. lGas Detection Instrumentation Using Electrically-Biased Fuel Cell Sensor Technology11, PB25W23, NTIS, Springfield, Va., 1978... 

Figure 2. Molecular beam mass spectrometer. Key A, nozzle-skimmer chamber B, middle chamber C, mass spectrometer chamber D, sampling nozzles E, skimmers F, choppers G, gate valve assembly H, mass spectrometer and I, nylon flanges permitting electrical biasing for detection of ions from coal burner.

Chae D-H, Krauss B, von Klitzing K, Smet JH (2010) Hot phonons in an electrically biased graphene constriction. Nano Lett 10 466-471... 

Electrospinning can create surface textures needed for superhydrophobicity. Electrospinning is a widely used technique to make ultra-thin polymer fibers. In this process, a polymer solution is charged in a capillary tube and electrically biased with respect to a grounded collector surface located 10 cm from the needle. The polymer solution is then ejected from the capillary into a jet form and the solvent evaporates leaving polymer fibers. By electrospinning polymers with hydrophobic properties, one can easily produce superhydrophobic fiber mats on the collector [89-92]. Of course, the electrospinning can also be used to make porous fiber mats... 

Excitation of additional carriers Photoconductivity Electrically biased Intrinsic Extrinsic... 

Riza et al. fabricated a three-terminal device for optical beam forming [6]. Figure 5.4 shows the top view of a thin film resistor-biased LC cylindrical lens, with electrical biasing resistors on the left and right sides of the active area. A spherical or elliptical lens can be formed by the appropriate use of a cascade of two such LC cylindrical lenses with orthogonal lens axes. 

Ionic conductivity results from an electrical biasing of the same self-diffusion process, such that down-field jumps occur more frequently than up-field jumps. This results in a net down-field drift of current density proportional to the field. Figure 2(a) shows a schematic illustration of this mechanism. 

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