Christopher Rutherglen

Electrical Properties of 0.4 cm Long Single-Walled Carbon Nanotubes

Centimeter scale aligned carbon nanotube arrays are grown from nanoparticle/metal catalyst pads. We find the nanotubes grow both “with” and “against the wind”. A metal underlayer provides in situ electrical contact to these long nanotubes with no post growth processing needed. Using the electrically contacted nanotubes, we study electrical transport of 0.4 cm long nanotubes. The source−drain I−V curves are quantitatively described by a classical, diffusive model. Our measurements show that the outstanding transport properties of nanotubes can be extended to the cm scale and can open the door to large scale integrated nanotube circuits with macroscopic dimensions.

Microwave nanotube transistor operation at high bias

We measure the small signal, 1GHz source-drain dynamical conductance of a back-gated single-walled carbon nanotube field effect transistor at both low and high dc bias voltages. At all bias voltages, the intrinsic device dynamical conductance at 1GHz is identical to the low frequency dynamical conductance, consistent with the prediction of a cutoff frequency much higher than 1GHz. This work represents a significant step towards a full characterization of a nanotube transistor for rf and microwave amplifiers.

Towards a single-chip, implantable RFID system: is a single-cell radio possible?

We present an overview of progress towards single-chip RFID solutions. To date heterogeneous integration has been appropriate for non-biological systems. However, for in-vivo sensors and even drug delivery systems, a small form factor is required. We discuss fundamental limits on the size of the form factor, the effect of the antenna, and propose a unified single-chip RFID solution appropriate for a broad range of biomedical in-vivo device applications, both current and future. Fundamental issues regarding the possibility of single cell RF radios to interface with biological function are discussed.

Nanotube technology for microwave applications

In this paper we present an overview of the high-frequency properties nanotube and nanowire technology for microwave applications. We discuss circuit models of the ac performance of active, ballistic 1d transistor structures, leading to the prediction that THz cutoff frequencies should be possible. Issues of economics and manufacturability, as well as device-to-device variation, constitute a major challenge to be met before the technology is ready for system insertion. Still, speed is one of the promises of nanotechnology, and nanotube and nanowire devices are worth serious consideration for microwave applications.

SINGLE-WALLED CARBON NANOTUBES: APPLICATIONS IN HIGH FREQUENCY ELECTRONICS

In this paper, we review the potential applications of single-walled carbon nanotubes in three areas: passives (interconnects), actives (transistors), and antennas. In the area of actives, potential applications include transistors for RF and microwave amplifiers, mixers, detectors, and filters. We review the experimental state of the art, and present the theoretical predictions (where available) for ultimate device performance. In addition, we discuss fundamental parameters such as dc resistance as a function of length for individual, single-walled carbon nanotubes.

Effect of source, surfactant, and deposition process on electronic properties of nanotube arrays

The electronic properties of arrays of carbon nanotubes from several different sources differing in the manufacturing process used with a variety of average properties such as length, diameter, and chirality are studied. We used several common surfactants to disperse each of these nanotubes and then deposited them on Si wafers from their aqueous solutions using dielectrophoresis. Transport measurements were performed to compare and determine the effect of different surfactants, deposition processes, and synthesis processes on nanotubes synthesized using CVD, CoMoCAT, laser ablation, and HiPCO.

Carbon nanotube antennas

A carbon nanotube is a one-dimensional molecular wire. In this paper, we discuss some of the properties of carbon nanotubes as microwave and mm-wave antennas. We also discuss some of the conceptual issues involved with understanding the interaction of microwaves with one-dimensional quantum wires. While we focus on simple dipole antennas, our discussion applies generally to the interaction of microwaves with nano-materials, including nanotube arrays and composites.