Highly conductive multi-walled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) nanocomposite for microfluidic applications

2020 ◽  
pp. 002199832097764
Author(s):  
Nasim Jan Mohammadi Dashtaki ◽  
Amir Hossein Nassajpour-Esfahani ◽  
Morteza Bayareh ◽  
Pouya Rezai ◽  
Ali Doostmohammadi
Keyword(s):  
Electric Fields ◽  
Microfluidic Devices ◽  
Microstructural Properties ◽  
Elemental Mapping ◽  
Conductive Materials ◽  
Ac Electric Fields ◽  
Ac Electric Field ◽  
Multi Walled Carbon Nanotube ◽  
Measured Field ◽  
Scanning Electron

Conductive materials are required for sensing and actuation purposes in microfluidic devices. Electrical and mechanical properties of aligned CNTs/PDMS nanocomposites fabricated in AC and quasi-AC electric fields were measured. Field emission scanning electron microscope and elemental mapping were used to evaluate the microstructural properties of fabricated specimens. Results showed that nanocomposite properties were dependent on CNT concentration. A homogenized and nonagglomerated composite was obtained using a quasi-AC electric field with the voltage of 1075 V zero to peak at a frequency of 100 Hz and current of 35 milliamps when applied to suspension for 2 hours at 80 °C. The aligned nanocomposite with 1 wt% of CNT exhibited an electrical conductivity, Young’s modulus, and tensile strength of 10-6 S/cm, 7.23 MPa, and 1.02 MPa, respectively.

UNDERSTANDING ELECTRIC INTERACTIONS IN SUSPENSIONS IN GRADIENT AC ELECTRIC FIELDS I: EXPERIMENTAL

2011 ◽  
Vol 25 (07) ◽  
pp. 919-925
Author(s):  
YAN SHEN ◽  
ZHIYONG QIU ◽  
SHIGERU TADA
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Corn Oil ◽  
Electrode Array ◽  
Ac Electric Fields ◽  
Ac Electric Field ◽  
Alpha Olefin ◽  
Dilute Suspensions ◽  
Spatially Periodic ◽  
Neutrally Buoyant

When neutrally buoyant poly alpha olefin particles in corn oil were exposed to a gradient ac electric field generated by a spatially periodic electrode array, these particles experienced the negative dielectrophoresis and instability in all the suspensions of concentration range from 0.01% to 5% (v/v). One critical particle concentration was experimentally determined as 1% (v/v) below which the particles in corn oil were segregated to form island-like structures in the lower electric field regions; and above which, particles only formed straight stripes. The island-like structure was suspended in the lowest electric field area. Specially designed experiments with a suspension of 1.126% (v/v) confirmed that there exists particle instability. Anisotropic properties of electric interactions are responsible for particle instability in all the suspensions of different concentrations and island-like structures were formed only in the dilute suspensions in which the particle instability has enough space to be developed.

Precise morphology control and fast merging of a complex multi-emulsion system: the effects of AC electric fields

Soft Matter ◽  
2019 ◽  
Vol 15 (28) ◽  
pp. 5614-5625 ◽  
Author(s):  
Yi Huang ◽  
Shuai Yin ◽  
Wen Han Chong ◽  
Teck Neng Wong ◽  
Kim Tiow Ooi
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Morphology Control ◽  
Emulsion System ◽  
Contact Type ◽  
Ac Electric Fields ◽  
Ac Electric Field

We showed a full morphology control over complex emulsions through an AC electric field by non-contact type of electrodes.

Directed Assembly of Nanoelements Using Electrostatically Addressable Templates

2005 ◽  
Vol 901 ◽  
Author(s):  
Xugang Xiong ◽  
Prashanth Makaram ◽  
Kaveh Bakhtari ◽  
Sivasubramanian Somu ◽  
Ahmed Busnaina ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electric Field ◽  
Electric Fields ◽  
Directed Assembly ◽  
Single Wall Carbon Nanotubes ◽  
Nanoparticle Assembly ◽  
Single Wall Carbon ◽  
Ac Electric Fields ◽  
Ac Electric Field ◽  
Dc Electric Field

AbstractDirected assembly of nanoparticles and single wall carbon nanotubes (SWNTs) using electrostatically addressable templates has been demonstrated. Nanoparticles down to 50 nm are assembled on the Au micro and nanowires of the templates in a DC and AC electric fields. The nanoparticles can be assembled in monolayers and thicker layers. Single wall carbon nanotubes (SWNTs) are also assembled without alignment on Au wires using the nanotemplate. As the size of the template wires is reduced to nanoscale dimensions, an AC electric field proves to be more effective for nanoparticle assembly than a DC electric field.

scholarly journals Editorial for the Special Issue on AC Electrokinetics in Microfluidic Devices

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 345
Author(s):  
Antonio Ramos ◽  
Pablo García-Sánchez
Keyword(s):  
Electric Fields ◽  
Microfluidic Devices ◽  
Special Issue ◽  
Small Particles ◽  
Ac Electrokinetics ◽  
Ac Electric Fields

The use of AC electric fields for manipulating and/or characterizing liquids and small particles in suspension is well-known [...]

Electric Trapping and Lysing of Cells in a Microchannel Constriction

2009 ◽  
Author(s):  
Christopher Church ◽  
Junjie Zhu ◽  
Guohui George Huang ◽  
Gaoyan Wang ◽  
Tzuen-Rong Jeremy Tzeng ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Cell Concentration ◽  
Ac Electric Fields ◽  
Ac Electric Field ◽  
Electrical Lysis ◽  
Smooth Switching ◽  
Dc Component ◽  
High Electric Fields ◽  
Pressure Driven Flow

Cell lysis is a necessary step in the analysis of intracellular contents. It has been recently demonstrated in microfluidic devices using four methods: chemical lysis, mechanical lysis, thermal lysis, and electrical lysis [1]. The locally high electric fields needed for electrical lysis have been achieved using micro-electrodes and micro-constrictions for pulsed and continuous DC electric fields, respectively. However, since the two determining factors of electrical lysis are field strength and exposure time, opposing pressure-driven flow must often be used in pure DC lysis to reduce the velocity of the cells and to ensure the cells spend sufficient time in the high electric field region [1,2]. Using DC-biased AC fields can easily fulfill these requirements as only the DC component contributes to cell electrokinetic transport. Prior to lysis, cell concentration can be increased by trapping using dielectrophoresis (DEP), which may occur with either DC or DC-biased AC electric fields [3,4]. This operation is useful in cases where the cell supply is limited or when the cell concentration is too low in general. In this work, red blood cells are used to demonstrate the smooth switching between electrical lysing and trapping in a microchannel constriction. The transition between lysis and trapping is realized by tuning the DC component in a DC-biased AC electric field.

UNDERSTANDING ELECTRIC INTERACTIONS IN SUSPENSIONS IN GRADIENT AC ELECTRIC FIELDS II: SIMULATIONS AND APPLICATION EXPLORATION

2011 ◽  
Vol 25 (07) ◽  
pp. 927-933
Author(s):  
SHIGERU TADA ◽  
YAN SHEN ◽  
DAVID JACQMIN ◽  
BINGMEI FU ◽  
ZHIYONG QIU
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Particle Concentration ◽  
Corn Oil ◽  
Critical Concentration ◽  
Md Simulations ◽  
Continuous Model ◽  
Dynamics Model ◽  
Ac Electric Fields ◽  
Ac Electric Field

We used numerical simulations of a continuous model and the molecular dynamics model to understand the particle instability, formation of island-like structures and existence of one critical particle concentration of 1% (v/v) for formation of island-like structures in the suspension in a gradient AC electric field reported in Paper I. The simulations of the continuous model show that the critical concentration of 1% (v/v) is the concentration of which the particles of a suspension are just fully filling the lower field region finally. According to the MD simulations, the particles instability does exist in the corn oil in a gradient AC electric field, anisotropic polarization interactions among the particles are responsible for the particle instability and have memory, and the memory is still kept even when the particles are transported by a dielectrophoresis force. The island-like structures can be regarded as signature of the memory. We explored possibilities to apply our findings in biomedical fields.

scholarly journals Improvement of Interfacial Shear Strength of Mendong Fiber (Fimbristylis globulosa) Reinforced Epoxy Composite Using the AC Electric Fields

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Heru Suryanto ◽  
Eko Marsyahyo ◽  
Yudy Surya Irawan ◽  
Rudy Soenoko ◽  
Aminudin
Keyword(s):  
Shear Strength ◽  
Electric Field ◽  
Electric Fields ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Epoxy Composites ◽  
Polymerization Process ◽  
Fiber Reinforced ◽  
Ac Electric Fields ◽  
Ac Electric Field

The effects of the AC electric field treatment on the interfacial shear strength of mendong fiber-reinforced epoxy composites were investigated. For this purpose, the epoxy (DGEBA) with a cycloaliphatic amine curing agent was treated by the AC electric field during the curing process. The heat generated during the epoxy polymerization process was monitored. Structure of the epoxy was studied by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscope, respectively. The interfacial shear strength (IFSS) was also measured using a single fiber pull-out test. XRD analyzes indicated that the treatment of AC electric fields was able to form a crystalline phase of epoxy. IFSS of the mendong fiber-reinforced epoxy composites was optimum increased by 38% in the AC electric fields treatment of 750 V/cm.

Fabrication of ZrO 2 /rGO nanocomposites by flash sintering under AC electric fields

2021 ◽  
Author(s):  
Xinghua Su ◽  
Mengying Fu ◽  
Gai An ◽  
Zhihua Jiao ◽  
Qiang Tian ◽  
...  
Keyword(s):  
Electric Fields ◽  
Ac Electric Fields ◽  
Flash Sintering

AC Electrokinetics for Biosensors

2004 ◽  
Author(s):  
M. Sigurdson ◽  
C. Meinhart ◽  
D. Wang
Keyword(s):  
Electric Fields ◽  
Dna Hybridization ◽  
Fluid Motion ◽  
Diffusive Transport ◽  
Analyte Concentration ◽  
Ac Electrokinetics ◽  
Ac Electric Fields ◽  
Binding Rate ◽  
Electrothermal Flow ◽  
Biosensor Device

We develop here tools for speeding up binding in a biosensor device through augmenting diffusive transport, applicable to immunoassays as well as DNA hybridization, and to a variety of formats, from microfluidic to microarray. AC electric fields generate the fluid motion through the well documented but unexploited phenomenon, Electrothermal Flow, where the circulating flow redirects or stirs the fluid, providing more binding opportunities between suspended and wall-immobilized molecules. Numerical simulations predict a factor of up to 8 increase in binding rate for an immunoassay under reasonable conditions. Preliminary experiments show qualitatively higher binding after 15 minutes. In certain applications, dielectrophoretic capture of passing molecules, when combined with electrothermal flow, can increase local analyte concentration and further enhance binding.

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