Direction Of Preferred Orientation Research Articles

Thermal and compositional fields to maneuver Cu6Sn5 intermetallic growth on (111) nanotwinned copper substrate

The microstructure of the Cu6Sn5 phase plays a pivotal role in the functionality of microbumps utilized in 3D packaging. In this study, we present an experimental methodology aimed at maneuvering the orientation and morphology of Cu6Sn5 grains formed on (111) nanotwinned Cu substrate, achieved through variations in reflow temperatures (260∘C and 300∘C) and initial Cu proportion in solder (ranging from 0 to 3.0 wt%). At 300∘C and lower initial Cu concentrations (0 and 0.7 wt%), irregularly arranged roof-type Cu6Sn5 grains exhibiting a pronounced {21¯1¯0} texture were observed. Conversely, typical scallop-type Cu6Sn5 grains displaying a specific preferential {21¯1¯3} texture were identified at this temperature for Cu concentrations of 1.5 and 3.0 wt% At 260∘C, the scallop-type morphology was solely present at all Cu composition variants. The differing rates of solute controlled intermetallic phase clustering mechanism at altered solubility limits and magnitudes of thermodynamic driving force for different temperatures, can decide the relative loss of interface coherency and subsequently change the preferred orientation direction of evolving interfacial structures. Our findings demonstrate that the precise control over soldering temperature, solder Cu composition, and the microstructure of Cu UBM can enable the attainment of Cu6Sn5 microstructure with a designated orientation and morphology.

How bumblebees coordinate path integration and body orientation at the start of their first learning flight.

The start of a bumblebee's first learning flight from its nest provides an opportunity to examine the bee's learning behaviour during its initial view of the nest's unfamiliar surroundings. Like many other hymenopterans, bumblebees store views of their nest surroundings while facing their nest. We found that a bumblebee's first fixation of the nest is a coordinated manoeuvre in which the insect faces the nest with its body oriented towards a particular visual feature within its surroundings. This conjunction of nest fixation and body orientation is preceded and reached by means of a translational scan during which the bee flies perpendicularly to its preferred body orientation. The utility of the coordinated manoeuvre is apparent during the bees' first return flight after foraging. Bees then adopt a similar preferred body orientation when close to the nest. How does a bee, unacquainted with its surroundings, know when it is facing its nest? A likely answer is through path integration, which gives bees continuously updated information about the current direction of their nest. Path integration also gives bees the possibility to fixate the nest when their body points in a desired direction. The three components of this coordinated manoeuvre are discussed in relation to current understanding of the central complex in the insect brain, noting that nest fixation is egocentric, whereas the preferred body orientation and flight direction that the bee adopts within the visual surroundings of the nest are geocentric.

Effects of Deposition Potential and Temperature on Co(II) Reduction and Electrocrystallization for Preparing Nanocrystalline Co Coatings in Ethylene Glycol Solution

Based on cyclic voltammetry (CV) and chronoamperometry (CA) experiments, the effects of deposition potential and temperature on Co(II) reduction and electrocrystallization in ethylene glycol (EG) are reported. CV observations show that Co(II) reduction reaction is irreversible, and both the equilibrium potential and nucleation overpotential, η nucleation, move to more positive values as the temperature is improved. The diffusion coefficient of Co(II) is 2.24 × 10−6 cm2 s−1 at 323 K and the activation energy for bulk diffusion (E bd) of Co(II) is 22.03 ± 0.8 kJ mol−1. CA observations show that the Co electrocrystallization mechanism is a 3D nucleation and growth of a new phase under diffusion control. Its mechanism is an instantaneous regime at 323 K at various applied potentials, however, the mechanism changes from a progressive nucleation to an instantaneous nucleation at −1.10 V as the temperature increases. The cobalt nuclei are spherical microstructure, and these innumerable spherical crystal particles can align compactly to form many wirelike crystals bundles. XRD observation confirms the characteristic peak of crystalline Co with a preferred orientation direction and the average size of Co grains is 19 nm. It is also found that the Co coating thickness is affect by the potential and temperature.

Structure and Solidification Process Observation of Fe-C-Cr Alloy Using Confocal Laser Scanning Microscope

In this study, we investigated the growth process of M7C3 carbide by a Confocal Laser Scanning Microscope. Fe-C-Cr alloy was prepared using an arc furnace. The composition was determined to be Fe:C:Cr=55:5:40(wt%). From the results of XRD and EPMA, the Fe-C-Cr alloy contained M7C3 carbide in the internal structure. In condition of two cooling rates 60°C/min and 30°C/min observed with a Confocal Laser Scanning Microscope. Corners of the Hexagonal structure grew in the preferred orientation direction of M7C3 carbide at 60°C/min. After the growth of preferred orientation direction, the M7C3 carbide formed to connect between the corners. At a cooling rate of 30°C/min, M7C3 carbides grew in oblique direction to the observation area. At the beginning, the structures were hidden in the fluid. But the structures started to grow, the shape of the hexagon became eventually. After the melting experiment, the samples were observed by Optical Microscope and Scanning Electron Microscope. As a result, since hexagonal structure arose a difference in height between the outside and the inside. M7C3 carbides grew from the outside in the solidification process.

A chiral-racemic lyotropic chromonic liquid crystal system.

The two main classes of liquid crystals are thermotropic (containing no solvent) and lyotropic (containing solvent). Both of these classes possess the nematic phase, the most simple of liquid crystal phases with only uniaxial orientational order. For both of these classes, if the constituent molecules are chiral or if a chiral dopant is added, the preferred direction of orientation rotates in helical fashion in what is called the chiral nematic phase. Recent research has shown that because the ordering entities of the two classes are quite different (molecules versus molecular assemblies), important differences in the properties of the nematic phase can result. While thermotropic chiral nematics have been extensively examined, less is known about lyotropic chiral nematics, especially for the most ideal case, a chiral-racemic system. Furthermore, none of the lyotropic chiral-racemic studies has included lyotropic chromonic liquid crystals, which are solutions of dyes, drugs, and nucleic acids. Inverse pitch measurements are reported for a chiral-racemic system of a chromonic liquid crystal across the entire chiral fraction range and over a 30 °C temperature interval. The inverse pitch depends linearly on chiral fraction and decreases with increasing temperature, indicating that achiral and chiral molecules participate in the assembly structure similarly. The helical twisting power is significantly larger than for other chiral lyotropic liquid crystals due to the very high scission energy of the investigated system.

Physical properties of Al-doped ZnS thin films prepared by ultrasonic spray technique

The objective of this work is study the effect of Al doping on physical properties of ZnS thin films. Undoped and Al-doped ZnS films were deposited by ultrasonic spray method using atomizer on glass substrates at 500°C. The films were synthesized with different Al doping ratio ranged from 0 to 6 %. The films structure and morphology were studied by means of X-ray diffraction (XRD), scanning electron microscopy. The films optical and electrical properties were studied by UV-VIS spectrophotometer and four probes method. The structural analysis indicated that the doped ZnS films have a hexagonal structure with strong preferred orientation (002) direction for all Al concentration. The (SEM) images revealed a dense surface, highly homogeneous and better adherent to the substrate surface. The average crystallites size increases from 32 nm to 43.8 nm with increasing of Al concentrations. UV–vis–NIR spectro-photometric measurements showed that the films were good transparent (60–73%) in the visible region. The films band gap is ranged from 3.7 eV to 3.9 eV. The performed electrical measurements indicate that the films electrical resistivity depends on the doping ratio. The latter was decreases with increasing the Al concentration from 8 × 104 to 3.35 × 104Ω.cm.

Argon vs. air atmosphere in close spaced vapor transport deposited tin sulfide thin films

The fundamental understanding and tailoring of material properties play a fundamental role on the performance of tin (II) sulfide (SnS)-based photovoltaic devices. In this regard, this work reports on the deposition of single-phase, p-type SnS thin films synthesized by close spaced vapor transport (CSVT) and the impact of employing argon (Ar) and bare vacuum (air) atmospheres on CSVT-SnS thin film properties is presented and compared for the first time. The analysis of film properties was performed by structural, directional, morphological, topographical, along with thermoelectric and optoelectronic characterizations of the samples. It is demonstrated that by changing the CSVT annealing atmosphere, the SnS grains change their orientation from perpendicular (respect to substrate) in Ar to parallel in a bare vacuumed (air) conditions. Furthermore, Hall measurements show that the hole concentration are mostly the same but that hole mobility depends, in turn, on the direction of preferred orientation of the SnS crystals. This translates into a twice higher lateral conductivity on the air- respect to the argon-SnS thin films. In this way, the different atmospheric exhibit a profound impact on the physical, morphological and structurally orientated properties of the SnS grains. These results demonstrate that photovoltaic grade p-type SnS films can be deposited in air without the need of an inert gas atmosphere which opens the way to a cost reduction in the fabrication of SnS-based photovoltaic devices.

Orientation behavior and swimming speed of Atlantic herring larvae (Clupea harengus) in situ and in laboratory exposures to rotated artificial magnetic fields

The dispersal of fish larvae during the early life stages plays an important role in recruitment. Together with oceanographic processes, larval orientation and swimming behavior significantly influences dispersal. However, currently there is no information of larval behavior in situ for most subpolar species. The Atlantic herring (Clupea harengus) is an ecologically and commercially important component of the North Atlantic ecosystem. This species has sustained a large fishery for over a century, and its stocks have experienced both dramatic collapse and recovery. The Atlantic herring is highly migratory, making it challenging for researchers to determine with certainty the structure and discreteness of different herring stocks. In this context, studying the behavior of herring larvae at sea is crucial for a deeper understanding of their dispersal. However, to date information on the orientation behavior and swimming abilities of herring larvae in situ is missing. In this study, we coupled in situ observations and laboratory experiments to investigate whether herring larvae display orientation when swimming in situ, and which mechanisms/cues they could use. We video recorded the orientation behavior of 208 herring larvae between 14 and 28 days post hatch (DPH) in the coastal Norwegian North Sea while they drifted in transparent behavioral chambers. We also tested the orientation of 136 larvae in a magnetic laboratory, in which they were deprived of any external cue and where we could modify the direction of the magnetic field. We report evidence that herring larvae have a significant preferred orientation direction to the southeast, which does not change between 14 and 28 DPH. Moreover, our results suggest that sunlight plays a key role as larvae had a highly significant orientation towards the sun during sunny weather, but they lost this ability, and exhibited lower precision in their orientation, under an overcast sky. We did not find evidence of magnetic compass orientation, indicating that the orientation direction of herring larvae is not magnetic, at least at this life history stage. Larvae swam at an average speed of 0.36–0.40 cm/s and reached maximum speeds of 3–3.36 cm/s. These results demonstrate that 14–28 DPH herring larvae are capable of orienting in situ. Possible implications of this orientation behavior for larval transport in Norwegian waters are also explored.

Enhanced strength and ductility in thin Ti-6Al-4V alloy components by alternating the thermal cycle strategy during plasma arc additive manufacturing

There is microstructural heterogeneity in titanium alloy deposited by high-energy-density beam additive manufacturing (AM) technologies in an as-built condition that leads to anisotropy of mechanical properties, especially poor ductility. To resolve this problem, use of an alternating thermal cycle strategy during plasma arc AM has been studied. The results show that the equivalent thermal balance is maintained in the process, preventing the coarsening microstructure from growing along a single direction. As a result of the change of the maximum temperature gradient, the close-packed plane growth of the α phase deviated from the preferred orientation direction; i.e., the α phase deviated from the growth of {0002} and {101¯0} planes in the vertical direction but {102¯0} and {101¯0} planes in the horizontal direction. The grain size and the width of lamellar α are refined, specially the layer band region. The horizontal as-built mechanical properties are higher than those of the forging standards, with elongation of 11.6 ± 0.2%, and 28 ± 1.8% reduction of area. Meanwhile, the average vertical tensile properties were also commensurate with the forging strength, thus anisotropy and heterogeneity of the microstructure and mechanical properties are effectively weakened without post heat treatment.

Electrochemical Behavior of Co(II) Reduction for Preparing Nanocrystalline Co Catalyst for Hydrogen Evolution Reaction from 1-ethyl-3-methylimidazolium Bisulfate and Ethylene Glycol System

The electrochemical behavior of Co(II) reduction and Co nucleation/growth process on glassy carbon (GC) electrode in 1-ethyl-3-methylimidazolium bisulfate ([EMIM]HSO4) ionic liquid (IL) and ethylene glycol (EG) system is investigated. Cyclic voltammetry (CV) measurements indicate that Co(II) reduction occurs by a one-step process, Co(II) to Co(0), and it is an irreversible reaction. The diffusion coefficient of Co(II) is 2.24 × 10−6 cm2 s−1 at 323 K in the system. Chronoamperometry measurements show that the growth/nucleation process of Co on GC electrode in [EMIM]HSO4-EG is a three-dimensional (3D) progressive nucleation at lower overpotentials and instantaneous nucleation at higher overpotentials under diffusion controlled growth process. These effects of electrodepositing potential, current density and temperature on Co coating thickness are also investigated. The Co coatings are observed by energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and X-ray diffractometer (XRD). SEM micrographs confirm that the Co coatings are relatively loose with a fibrous surface morphology. XRD pattern of the prepared coating reveals the characteristic peak of crystalline Co with a preferred orientation direction and the average size of Co grains is 11 nm. The nanocrystalline Co coating exhibits an excellent catalytic activity and stability for hydrogen evolution reaction (HER) in alkaline medium.

Codeposition of Nanocrystalline Co-Ni Catalyst Based on 1-ethyl-3-methylimidazolium Bisulfate and Ethylene Glycol System for Hydrogen Evolution Reaction

The codeposition behavior of Co(II) and Ni(II) in 1-ethyl-3-methylimidazolium bisulfate ([EMIM]HSO4) ionic liquid (IL) and ethylene glycol (EG) system is recorded using cyclic voltammetry (CV). The result indicates that the mechanism of Co-Ni codeposition is an anomalous codeposition, and both the inhibition for Ni(II) reduction and the anomalous codeposition phenomena can be improved by the increase of Co(II) concentration in the system. These Co-Ni deposits are characterized using EDS, XRD and SEM. SEM micrographs indicate that the surface morphology of Co-Ni deposits can be changed by the increase of Co content, and these deposits with many additional elongated acerose crystals, which are germinated on the spherical “nodules” surface, can be prepared. XRD pattern reveals the feature peak of crystalline Co1.2Ni2.8 with a preferred orientation direction and the average size of grains is calculated to be about 14.6 nm. Moreover, the electrocatalytic activity for hydrogen evolution reaction (HER) on the prepared Co-Ni catalyst surface is investigated using linear sweep voltammetry (LSV) and electrochemical impedance spectra (EIS). These results indicate that the obtained catalyst presents an excellent electrocatalytic activity and durability for HER with an overpotential of 139 mV at 10 mA cm−2 in 1 M KOH solution.

Temperature dependence of the pitch in chiral lyotropic chromonic liquid crystals.

One of the most simple cases in which chirality at the microscopic level produces a chiral macroscopic structure is the chiral nematic liquid crystal phase. In such a phase, the preferred direction of molecular orientation rotates in helical fashion, with the pitch of the helix in different systems ranging from around 100 nm to as large as can be measured (∼10 mm). For almost all thermotropic and lyotropic liquid crystals, the ordered entities are formed from strong bonds, so the pitch varies in accordance with how the interactions between these largely immutable entities are affected by changing conditions. A unique exception are lyotropic chromonic liquid crystals (LCLCs) that spontaneously form weakly bound assemblies in solution, the size of which depends strongly on experimental parameters. While the temperature dependence of the pitch has been measured for chiral LCLCs formed by short strands of DNA (DNA-LCLCs), such is not the case for chiral LCLCs formed by small molecules. Polarized optical microscopy experiments on small molecule chiral LCLCs reveal the changing assembly size through a temperature dependence of the pitch not typical for many other systems, including the most recent measurements on DNA-LCLCs. In fact, the pitch measurements in small molecule chiral LCLCs strongly increase in value as the temperature is increased and the assemblies shrink in size. Theoretical considerations provide some help in understanding this phenomena, but leave much to be explained.

EBSD study of beam speed effects on Ti-6Al-4V alloy by powder bed electron beam additive manufacturing

Electron Beam Additive Manufacturing (EBAM) has a lot of advantages and has become an attractive manufacturing method to produce the Ti-6Al-4V alloy. In this study, four Ti-6Al-4V rectangular blocks were manufactured by the EBAM process with four different beam scanning speeds (Speed Function x- SF20, SF36, SF50, and SF65). Based on the experimental results, the beam scanning speed did show notable effects on the preferred orientation of the α phase in the Z-plane which presents a relatively strong <21¯1¯4> and <101¯0> texture. However, with the increase of the beam speed, the intensity of the texture in the Z-plane decreases first and then increases. For the Y-plane, the preferred orientation direction of α changes from <21¯1¯1> (SF20), <0001> (SF36, SF50) to <101¯2> (SF65) with their maximum intensity decreased from 13.58 to 8.85 times of the random intensity. Generally, the parts did not show outstanding anisotropic characteristics in hardness and elastic modulus. The SF50 sample presents the highest properties (Vickers hardness and elastic modulus) between the four parts, which results from its finest microstructure and the weakest texture.

Measuring spatio-temporal dynamics of impervious surface in Guangzhou, China, from 1988 to 2015, using time-series Landsat imagery

This study evaluated the spatio-temporal change characteristics of urban development at different scales with time-series impervious surface fractions. Landsat-5 Thematic Mapper (TM) and Landsat-8 Operational Land Imager (OLI) images were used to extract impervious surface fractions using a modified linear spectral mixture analysis method in Guangzhou from 1988 to 2015. The results indicated that the impervious surface area has substantially increased, from 70.3 km2 in 1988 to 580.5 km2 in 2015. In 2015, the impervious surfaces were distributed almost throughout the whole region of the study area, except in the forest region. Next, impervious surface weighted mean centre (ISWMC) and the standard deviational ellipse (SDE) methods were used to systematically analyse the principle orientation, direction, spatio-temporal expansion trends, and the distribution differences of impervious surfaces at the whole and local region scales from 1988 to 2015. The spatio-temporal dynamics of ISWMC exhibited different expansion directions and intensities of impervious surfaces at the whole and local region scales. On a whole region scale, the principle expansion direction of impervious surfaces was northward. However, the expansion trend of impervious surfaces in the different districts was significantly different from other trends at the local region scale. The parameters of SDE were used to investigate the orientation and the clustering or dispersion degree of impervious surface at different scales. The results from SDE analysis indicated that the impervious surfaces exhibited uncertainty in the expansion direction at the whole region scale; in contrast, they had a distinct preferred orientation and expansion direction at the local region scale. The analysis revealed that urban expansion exhibited different change characteristics in various directions at the local region scale. In summary, the results at the local region scale can better reflect the change trajectory of spatio-temporal dynamics of urban development and its fine spatial structure than at the whole region scale.

Ga-doped ZnO nanoparticles synthesized by sonochemical-assisted process

In this work, the experimental work has been conducted on the synthesis of Gallium (Ga)- doped zinc oxide (ZnO) nanoparticles with different doping concentration (0-5% at.) via sonochemical process. The precursors of Ga-doped ZnO nanoparticle were sourced by zinc acetate dehydrate and gallium (III) nitrate hydrate, respectively. Ammonia (NH3) was chosen as a precipitating agent in sonochemical process. The sonochemical time was operated for 10 min by a direct-immersion ultrasonic horn using Sonic model VCX 750 (750W, 20 KHz). Structural properties and morphologies were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that Ga doped ZnO powder after the synthesis were obtained in ultrafine structure that different form with pure ZnO. XRD analysis revealed that the pattern of Ga doped ZnO powder showed good crystallinity with the wurtzite structure due to the preferred orientation direction and crystallization. Ga doping concentration plays a key role in significant change of ZnO structures.

Dynamic states of swimming bacteria in a nematic liquid crystal cell with homeotropic alignment

Flagellated bacteria such as Escherichia coli and Bacillus subtilis exhibit effective mechanisms for swimming in fluids and exploring the surrounding environment. In isotropic fluids such as water, the bacteria change swimming direction through the run-and-tumble process. Lyotropic chromonic liquid crystals (LCLCs) have been introduced recently as an anisotropic environment in which the direction of preferred orientation, the director, guides the bacterial trajectories. In this work, we describe the behavior of bacteria B. subtilis in a homeotropic LCLC geometry, in which the director is perpendicular to the bounding plates of a shallow cell. We demonstrate that the bacteria are capable of overcoming the stabilizing elastic forces of the LCLC and swim perpendicularly to the imposed director (and parallel to the bounding plates). The effect is explained by a finite surface anchoring of the director at the bacterial body; the role of surface anchoring is analyzed by numerical simulations of a rod realigning in an otherwise uniform director field. Shear flows produced by a swimming bacterium cause director distortions around its body, as evidenced both by experiments and numerical simulations. These distortions contribute to a repulsive force that keeps the swimming bacterium at a distance of a few micrometers away from the bounding plates. The homeotropic alignment of the director imposes two different scenarios of bacterial tumbling: one with an 180° reversal of the horizontal velocity and the other with the realignment of the bacterium by two consecutive 90° turns. In the second case, the angle between the bacterial body and the imposed director changes from 90° to 0° and then back to 90°; the new direction of swimming does not correlate with the previous swimming direction.

Modifying exchange bias effects of Mn/NiFe bilayers by in-situ Ar+ bombardment

In this work, we present a procedure to modify the exchange bias (EB) properties of antiferromagnetic Mn/ferromagnetic NiFe bilayers by in-situ low energy Ar+ bombardment of the Mn layer during sample deposition. We present structural and magnetic results for unassisted and Ar+ assisted Mn/NiFe bilayers. X-ray diffraction, transmission electron microscopy and electron diffraction results establish different preferred Mn orientation directions between the two samples as a result of the Ar+ bombardment process. Hysteresis loops taken over several temperatures reveal that samples assisted with Ar+ ions during the Mn layer deposition had suppressed EB properties at low temperature as compared to samples grown without Ar+ assistance.

Orientation evolution of single-crystal superalloys under different solidification interface

The single-crystal superalloys with different deviation angle are prepared by using the liquid metal cooling high-temperature gradient directional solidification furnace, and the orientation evolution of single-crystal superalloys under different solidification interface is studied. The results indicate that the increase of the deviation angle will make the planar interface unstable. With the increase of the solidification rate, the growth direction of the crystal will deviate from the direction of heat flow to the preferred orientation direction. Under the developed dendrite crystal growth, the branches of the dendrite will follow the preferred orientation, nearly free from the effect of the heat flow.

Polarized wave electromagnetic shielding of anisotropic carbon nanomodifier-based LLDPE composites

The polarized wave electromagnetic shielding (EM SE) of nanocomposites containing 10 vol% of carbon nanomodifiers in a semicrystalline matrix is reported. Heat-treated carbon nanofibers, Pyrograf® III PR-19 heat treatment (HT) and multiwalled carbon nanotubes (MWNT) HT were dispersed in a linear low-density polyethylene matrix to produce flow-induced orientation of the nanomodifiers in the spun microfilaments. Consequently, the electrical conductivity of the resulting nanocomposites exhibited anisotropic behavior due to the nanomodifier orientation. The in-plane conductivity in the longitudinal direction (PR-19 HT comp.: ∼0.02 S/m; MWNT HT comp.: ∼3 S/m) was at least an order of magnitude higher than that along the transverse direction. As measured with a rectangular waveguide (WR510, 1.45–2.2 GHz), the PR-19 HT- and MWNT HT-oriented nanocomposites (1-mm thick) displayed EM SE values of 0.7 dB and 3.0 dB, respectively, when the nanomodifiers were transversely oriented with the polarized electric field. In contrast, when the orientation of the nanomodifiers was parallel with the field, EM SE values of 3.2 and 9.0 dB were obtained, respectively. The higher EM SE values are consistent with high conductivities observed in the direction of preferred orientation of the modifiers. POLYM. ENG. SCI., 55:299–307, 2015. © 2014 Society of Plastics Engineers

Liquid crystal electrography: Electric field mapping and detection of peak electric field strength in AlGaN/GaN high electron mobility transistors

The liquid crystal mixture E7, based on cyanobiphenyl, has been successfully employed to map electric field strength and distribution in AlGaN/GaN high electron mobility transistors. Using a transmitted light image through crossed polarizers the optical response of the liquid crystal deposited onto the surface of the devices was recorded as a function of source–drain bias, Vds. At a critical voltage of 4V the preferred direction of orientation of the long axes of the liquid crystal molecules in the drain access region aligned with one of the polarizers resulting in reduced transmitted light intensity. This indicates that at this electric field strength molecule orientation in most of the liquid crystal film is dominated by the electric field effect rather than the influence of surface anchoring. The experimental results were compared to device simulations. Electric field strength above the surface at Vds=4V was simulated to reach or exceed 0.006MV/cm. This electric field is consistent with the field expected for E7 to overcome internal elastic energy. This result illustrates the usefulness of liquid crystals to directly determine and map electric fields in electronic devices, including small electric field strengths.