Manipulation and assembly behavior of Spirulina-templated microcoils in the electric field

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76716-76723 ◽  
Author(s):  
Xinghao Li ◽  
Jun Cai ◽  
Lili Sun ◽  
Yue Yue ◽  
Deyuan Zhang

Manipulation and assembly of complicated metallic Spirulina-templated microcoils can be achieved through alternating electric fields.

2020 ◽  
Vol 30 (4) ◽  
pp. 46-51
Author(s):  
B. P. Sharfarets ◽  

The hydrodynamics of electrophoresis under the simultaneous impact of constant and alternating electric fields is considered. It has been shown that when the constant and alternating external fields are combined, the energy of the constant electric field is transferred into the alternating hydrodynamic field. An example is given of a dispersed medium in which a giant dispersion of the dielectric constant can arise, which in turn can contribute to an increase in the total electrophoresis rate. Analogies of the behavior of the considered dispersed medium with the action of an electroacoustic transducer based on the use of electrokinetic phenomena are given.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260967
Author(s):  
Iman Rad ◽  
Rainer Stahlberg ◽  
Kurt Kung ◽  
Gerald H. Pollack

Low frequency electric fields were exposed to various water samples using platinum electrodes mounted near the water surface. Responses were monitored using a spectro-radiometer and a contact-angle goniometer. Treatment of DI (deionized), EZ (Exclusion Zone), and bulk water with certain electromagnetic frequencies resulted in a drop of radiance persisting for at least half an hour. Compared to DI water, however, samples of EZ and bulk water showed lesser radiance drop. Contact-angle goniometric results confirmed that when treated with alternating electric fields (E = 600 ± 150 V/m, f = 7.8 and 1000 Hz), droplets of EZ and bulk water acquired different charges. The applied electric field interacted with EZ water only when electrodes were installed above the chamber, but not beneath. Further, when DI water interacted with an electric field applied from above (E = 600 ± 150 V/m, f = 75 Hz), its radiance profile became similar to that of EZ water. Putting these last two findings together, one can say that application of an electric field on DI water from above (E = 600 ± 150 V/m, f = 7.8 to 75 Hz) may induce a molecular ordering in DI water similar to that of EZ water.


2019 ◽  
Vol 31 (2) ◽  
pp. 277-287
Author(s):  
Evguenia Korobko ◽  
Leonid Makhnach ◽  
Zoya Novikova ◽  
Inga Kharlamova ◽  
Katya Novik

The rheological behavior of electrorheological fluids with dispersed fillers whose particles have different crystalline structures is investigated in direct and alternating electric fields. The dielectric characteristics of the materials were measured and the influence of the strength, frequency, and shape of the signal of electric field was investigated, and the influence of temperature on the shear stress in electrorheological fluids was estimated in direct current electric field.


2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.


2001 ◽  
Vol 87 (16) ◽  
Author(s):  
Richard A. Gray ◽  
Oleg A. Mornev ◽  
José Jalife ◽  
Oleg V. Aslanidi ◽  
Arkady M. Pertsov

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jingjun Wu ◽  
Zao Yi ◽  
Xin Ye ◽  
...  

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm2. The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Marie C. Lefevre ◽  
Gerwin Dijk ◽  
Attila Kaszas ◽  
Martin Baca ◽  
David Moreau ◽  
...  

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1398
Author(s):  
Yong-Qi Zhang ◽  
Xuan Wang ◽  
Ping-Lan Yu ◽  
Wei-Feng Sun

Trimethylolpropane triacrylate (TMPTA) as a photoactive crosslinker is grafted onto hydrophobic nanosilica surface through click chemical reactions of mercapto double bonds to prepare the functionalized nanoparticles (TMPTA-s-SiO2), which are used to develop TMPTA-s-SiO2/XLPE nanocomposites with improvements in mechanical strength and electrical resistance. The expedited aging experiments of water-tree growth are performed with a water-knife electrode and analyzed in consistence with the mechanical performances evaluated by means of dynamic thermo-mechanical analysis (DMA) and tensile stress–strain characteristics. Due to the dense cross-linking network of polyethylene molecular chains formed on the TMPTA-modified surfaces of SiO2 nanofillers, TMPTA-s-SiO2 nanofillers are chemically introduced into XLPE matrix to acquire higher crosslinking degree and connection strength in the amorphous regions between polyethylene lamellae, accounting for the higher water-tree resistance and ameliorated mechanical performances, compared with pure XLPE and neat-SiO2/XLPE nanocomposite. Hydrophilic TMPTA molecules grafted on the nano-SiO2 surface can inhibit the condensation of water molecules into water micro-beads at insulation defects, thus attenuating the damage of water micro-beads to polyethylene configurations under alternating electric fields and thus restricting water-tree growth in amorphous regions. The intensified interfaces between TMPTA-s-SiO2 nanofillers and XLPE matrix limit the segment motions of polyethylene molecular chains and resist the diffusion of water molecules in XLPE amorphous regions, which further contributes to the excellent water-tree resistance of TMPTA-s-SiO2/XLPE nanocomposites.


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