Biomedical subjects

Kristian Mølhave

Publications and source records attributed to Kristian Mølhave.

5 recordsLinked to original sources

PubMed2006

Transmission electron microscopy study of individual carbon nanotube breakdown caused by Joule heating in air.

We present repeated structural and electrical measurements on individual multiwalled carbon nanotubes, alternating between electrical measurements under ambient conditions and transmission electron microscopy (TEM). The multiwalled carbon nanotubes made by chemical vapor deposition were manipulated onto cantilever electrodes extending from a specially designed microfabricated chip. Repeated TEM investigations were then made of the progressive destruction of the nanotube structure induced by Joule heating in air. The electrical measurements indicate that the studied nanotubes behave as diffusive conductors with remarkably predictable electrical properties despite extensive structural damage.

Air↗

PubMed2006

Versatile method for manipulating and contacting nanowires.

We present a simple, non-lithographic method for electrically connecting nanowires with electrodes on planar as well as non-planar microsystems. A rigid nanowire is used as a local shadow mask during deposition of metal contacts, which we use to contact structures of widely different conductances: Multiwalled carbon nanotubes, para-hexaphenylene nanofibers, as well as indium arsenide and indium phosphide nanowires. Finally we demonstrate how the method can be extended to different electrode materials on each side of the electrode gap, as well as for investigation of the electromechanical properties of a nanowire integrated in a cantilever.

Electric Conductivity↗

PubMed2005

A simple electron-beam lithography system.

A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 microm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 nm. We demonstrate how the EBL system can be used to write three-dimensional nanostructures by electron-beam deposition.

Equipment Design↗

PubMed2004

Towards pick-and-place assembly of nanostructures.

We examine an approach to three-dimensional pick-and-place assembly of wire-like nanoscale components, such as carbon nanotubes and silicon nanowires, on microstructures inside a scanning electron microscope. In this article we demonstrate that microfabricated electrostatically acutuated tweezers can pick up silicon nanowires and show how electron beam deposition of carbon residues can be used to assemble carbon nanotubes on microelectrodes.

Equipment Design↗

PubMed2002

Stability of Coulomb crystals in a linear Paul trap with storage-ring-like confinement.

We report experiments on the stability of ion Coulomb crystals in a linear Paul trap with storage-ring-like confinement. The transverse dynamics of charged particles in a trap of this type is analogous to that of a fast beam traveling through a channel with periodic, magnetic alternating gradient confinement. The experimentally observed stability conditions for stationary crystals comply remarkably well with current theory of crystalline plasmas and beams.

Journal Article↗