University of California

Arun Majumdar

Peidong Yang

Rong Fan

Yiying Wu

Timothy David Sands

Richard E Russo

Ali Shakouri

Samuel S Mao

Eicke R Weber

Hannes Kind

Haoquan Yan

Henning Feick

Michael Huang

Rongrui He

Joshua Goldberger

Deyu Li

Rohit Nandkumar Karnik

Srinath Satyanarayana

Min Yue

Yi-Ying Wu

Mohammed Dahleh

James Samir Ismail

Kenneth Castelino

One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as 'nanowires', include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

Methods of fabricating nanostructures and nanowires and devices fabricated therefrom

A functionalized nanofluidic channel and method for functionalization that provides control over the ionic environment and geometry of the nanofluidic channel with the immobilization of biomolecules on the inner surface of the channel and use of high ionic concentration solutions. In one embodiment, the surface charge of the nanochannel is controlled with the immobilization of a protein such as streptavidin in the nanochannel. In another embodiment, the biomolecules are receptors and changes in nanochannel conductance indicates ligand binding events. The functionalized nanofluidic channel can be easily adapted for use with microchannel arrays.

Functionalization of nanofluidic channels

Fluidic nanotube devices are described in which a hydrophilic, non-carbon nanotube, has its ends fluidly coupled to reservoirs. Source and drain contacts are connected to opposing ends of the nanotube, or within each reservoir near the opening of the nanotube. The passage of molecular species can be sensed by measuring current flow (source-drain, ionic, or combination). The tube interior can be functionalized by joining binding molecules so that different molecular species can be sensed by detecting current changes. The nanotube may be a semiconductor, wherein a tubular transistor is formed. A gate electrode can be attached between source and drain to control current flow and ionic flow. By way of example an electrophoretic array embodiment is described, integrating MEMs switches. A variety of applications are described, such as: nanopores, nanocapillary devices, nanoelectrophoretic, DNA sequence detectors, immunosensors, thermoelectric devices, photonic devices, nanoscale fluidic bioseparators, imaging devices, and so forth.

Fluidic nanotubes and devices

A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

Composite sensor membrane

Methods of fabricating uniform nanotubes are described in which nanotubes were synthesized as sheaths over nanowire templates, such as using a chemical vapor deposition process. For example, single-crystalline zinc oxide (ZnO) nanowires are utilized as templates over which gallium nitride (GaN) is epitaxially grown. The ZnO templates are then removed, such as by thermal reduction and evaporation. The completed single-crystalline GaN nanotubes preferably have inner diameters ranging from 30 nm to 200 nm, and wall thicknesses between 5 and 50 nm. Transmission electron microscopy studies show that the resultant nanotubes are single-crystalline with a wurtzite structure, and are oriented along the &#x3c;001&#x3e; direction. The present invention exemplifies single-crystalline nanotubes of materials with a non-layered crystal structure. Similar 'epitaxial-casting' approaches could be used to produce arrays and single-crystalline nanotubes of other solid materials and semiconductors. Furthermore, the fabrication of multi-sheath nanotubes are described as well as nanotubes having multiple longitudinal segments.

Sacrificial template method of fabricating a nanotube

Nanowires, nanostructures and devices fabricated therefrom

A modified Atomic Force Microscope (AFM), which can machine and image the surface of a sample with nanometer precision in all three orthogonal directions by varying the depth-of-cut of the sample. A multi-repetitive sensor system is provided as is a radially halved quartered electrode to substantially maintain parallelism or substantial parallelism.

Automated tool for precision machining and imaging

Growing community of inventors

Orinda, CA, United States of America

Arun Majumdar