Dielectrophoretic Deposition and Alignment of Carbon Nanotubes

Wang, Xue; Li, Pengfei

doi:10.5772/16487

Cited by 18 publications

(17 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“… 4 , 35 The transport and trapping properties of DEP can also be employed as a means to control large-scale or even single-SWNT deposition for electronic applications. 36 , 37 Inhomogeneous electric fields for AC DEP can be generated in two different ways: (i) by introducing microelectrodes in a sample chamber or (ii) by constructing topological structures between macroelectrodes. 38 Electrode-based DEP (eDEP) is an established method where micrometer-sized electrodes are patterned on a substrate.…”

mentioning

confidence: 99%

Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis

2017

View full text Add to dashboard Cite

Single-walled carbon nanotubes (SWNTs) offer unique electrical and optical properties. Common synthesis processes yield SWNTs with large length polydispersity (several tens of nanometers up to centimeters) and heterogeneous electrical and optical properties. Applications often require suitable selection and purification. Dielectrophoresis is one manipulation method for separating SWNTs based on dielectric properties and geometry. Here, we present a study of surfactant and single-stranded DNA-wrapped SWNTs suspended in aqueous solutions manipulated by insulator-based dielectrophoresis (iDEP). This method allows us to manipulate SWNTs with the help of arrays of insulating posts in a microfluidic device around which electric field gradients are created by the application of an electric potential to the extremities of the device. Semiconducting SWNTs were imaged during dielectrophoretic manipulation with fluorescence microscopy making use of their fluorescence emission in the near IR. We demonstrate SWNT trapping at low-frequency alternating current (AC) electric fields with applied potentials not exceeding 1000 V. Interestingly, suspended SWNTs showed both positive and negative dielectrophoresis, which we attribute to their ζ potential and the suspension properties. Such behavior agrees with common theoretical models for nanoparticle dielectrophoresis. We further show that the measured ζ potentials and suspension properties are in excellent agreement with a numerical model predicting the trapping locations in the iDEP device. This study is fundamental for the future application of low-frequency AC iDEP for technological applications of SWNTs.

show abstract

mentioning

confidence: 99%

Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis

2017

View full text Add to dashboard Cite

show abstract

“…Here, the curves are related to the different gate voltage. The high linearity of the curves shows that most of the deposited CNT(s) were metallic (low-bandgap semiconductor) [40]. Figures 7 and 8 show the current for several V g and V SD voltages in two Fig.…”

Section: Resultsmentioning

confidence: 98%

Frequency dependence of dielectrophoretic fabrication of single-walled carbon nanotube field-effect transistors

et al. 2020

View full text Add to dashboard Cite

A new theoretical model for the dielectrophoretic (DEP) fabrication of single-walled carbon nanotubes (SWCNTs) is presented. A different frequency interval for the alignment of wide-energy-gap semiconductor SWCNTs is obtained, exhibiting a considerable difference from the prevalent model. Two specific models are study, namely the spherical model and the ellipsoid model, to estimate the frequency interval. Then, the DEP process is performed and the obtained frequencies (from the spherical and ellipsoid models) are used to align the SWCNTs. These empirical results confirm the theoretical predictions, representing a crucial step towards the realization of carbon nanotube field-effect transistors (CNT-FETs) via the DEP process based on the ellipsoid model.

show abstract

“…13 AC electrophoresis retains CNT bundles in the electron gap thus enabling them to serve as good candidates for gas-sensing elements 14 using dielectrophoretic forces to propagate the CNT along the electric field lines onto the electrodes. 15 Various voltages and frequencies were used to test the conductivity of the DEP process. Parameters with either 1 or 10 peak-to-peak voltages ( V p–p ) did not result in conductive current vs voltage measurements (SI Table S1 and Figure S2).…”

Section: Experimental Methodsmentioning

confidence: 99%

Chemically Enhanced Polymer-Coated Carbon Nanotube Electronic Gas Sensor for Isopropyl Alcohol Detection

et al. 2018

View full text Add to dashboard Cite

Breathing-air quality within commercial airline cabins has come under increased scrutiny because of the identification of volatile organic compounds (VOCs) from the engine bleed air used to provide oxygen to cabins. Ideally, a sensor would be placed within the bleed air pipe itself, enabling detection before it permeated through and contaminated the entire cabin. Current gas-phase sensors suffer from issues with selectivity, do not have the appropriate form factor, or are too complex for commercial deployment. Here, we chose isopropyl alcohol (IPA), a main component of de-icer spray used in the aerospace community, as a target analyte: IPA exposure has been hypothesized to be a key component of aerotoxic syndrome in pre, during, and postflight. IPAs proposed mechanism of action is that of an anesthetic and central nervous system depressant. In this work, we describe IPA sensor development by showing (1) the integration of a polymer as an IPA capture matrix, (2) the adoption of a redox chemical additives as an IPA oxidizer, and (3) the application of carbon nanotubes as an electronic sensing conduit. We demonstrate the ability to not only detect IPA at 100–10 000 ppm in unfiltered, laboratory air but also discriminate among IPA, isoprene, and acetone, especially in comparison to a typical photoionization detector. Overall, we show an electronic device that operates at room temperature and responds preferentially to IPA, where the increase in the resistance corresponds directly to the concentration of IPA. Ultimately, this study opens up the pathway to selective electronic sensors that can enable real-time monitoring in a variety of environments for the force health prevention and protection, and the potential through future work to enable low parts-per-million and possibly high parts-per-billion selective detection of gas-phase VOCs of interest.

show abstract

Dielectrophoretic Deposition and Alignment of Carbon Nanotubes

Cited by 18 publications

References 36 publications

Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis

Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis

Frequency dependence of dielectrophoretic fabrication of single-walled carbon nanotube field-effect transistors

Chemically Enhanced Polymer-Coated Carbon Nanotube Electronic Gas Sensor for Isopropyl Alcohol Detection

Contact Info

Product

Resources

About