University of California

Lawrence Livermore National Security, LLC

Nanomix, Inc.

Apple Inc.

William E Mickelson

Alexander K Zettl

Alex Zettl

Marcus A Worsley

Ying-Lan Chang

John Loren Passmore

Kenneth Jensen

Christian Valcke

Bradley N Johnson

Sergei Skarupo

Craig Bryant

Michael Rousseas

Leta Woo

Oleksandr Kuzmych

Thang Pham

Jeffrey C Grossman

Jean-Christophe P Gabriel

Caglar Girit

Anna P Goldstein

Aidin Fathalizadeh

Richard Yeh

David MacNeil

Gregory B Arndt

Roberto M Ribeiro

Jean-Christophe Gabriel

Roya Maboudian

Hu Long

Anna Harley-Trochimczyk

Carlo Carraro

This disclosure provides systems, methods, and apparatus related to boron nitride nanomaterials. In one aspect, a method includes generating a directed flow of plasma. A boron-containing species is introduced to the directed flow of the plasma. Boron nitride nanostructures are formed in a chamber. In another aspect, a method includes generating a directed flow of plasma using nitrogen gas. A boron-containing species is introduced to the directed flow of the plasma. The boron-containing species can consist of boron powder, boron nitride powder, and/or boron oxide powder. Boron nitride nanostructures are formed in a chamber, with a pressure in the chamber being about 3 atmospheres or greater.

System and methods for fabricating boron nitride nanostructures

Aspects of the subject technology relate to electronic devices with pressure sensors. A pressure sensor in a portable electronic device may include an integrated heater or may be co-operated with an external heater for the pressure sensor. The heater may be operated to heat some or all of the pressure sensor for pressure sensor testing, calibration, or temperature-controlled pressure sensing operations.

Electronic devices having pressure sensors with heaters

A solid-state, low power microheater sensor platform that is configurable with selected metal oxide films for particular gas sensing applications is described. The sensor platform is configured by selecting a chemiresistive or catalytic material that is suitable for detecting a desired gas and then forming a porous nanostructured film on the designated surfaces of the microheater platform. Also described are methods for creating a highly porous, nanostructured metal oxide film in a controlled location from a liquid precursor using a localized heat source. By fast annealing deposited liquid precursors with the microheater, a highly porous, nanocrystalline metal oxide film can be generated in-situ and locally on the sensor platform.

In-situ localized growth of porous metal oxide films on microheater platform for low temperature gas detection

Disclosed here is a composition comprising at least one graphene aerogel comprising a three-dimensional structure of graphene sheets, wherein the graphene sheets are covalently interconnected, and wherein the graphene aerogel is highly crystalline. Also described is a method for making a graphene aerogel, comprising preparing a mixture comprising a graphene oxide suspension and at least one catalyst; curing the reaction mixture to produce a wet gel; drying the wet gel to produce a dry gel; and pyrolyzing the dry gel at a temperature of 1500-3500&#xb0; C. to produce the graphene aerogel.

Highly crystalline 3D graphene

This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxide and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.

Crystalline boron nitride aerogels

Gas sensors are provided. The gas sensors include a gas sensing element having metal oxide nanoparticles and a thin-film heating element. Systems that include the gas sensors, as well as methods of using the gas sensors, are also provided. Embodiments of the present disclosure find use in a variety of different applications, including detecting whether an analyte is present in a gaseous sample.

Nanoparticle-based gas sensors and methods of using the same

This disclosure provides methods and materials related to boron nitride aerogels. In one aspect, a material comprises an aerogel comprising boron nitride. The boron nitride has an ordered crystalline structure. The ordered crystalline structure may include atomic layers of hexagonal boron nitride lying on top of one another, with atoms contained in a first layer being superimposed on atoms contained in a second layer.

This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

Boron nitride converted carbon fiber

Sensors and detection systems suitable for measuring analytes, such as biomolecule, organic and inorganic species, including environmentally and medically relevant volatiles and gases, such as NO, NO2, CO2, NH3, H2, CO and the like, are provided. Certain embodiments of nanostructured sensor systems are configured for measurement of medically important gases in breath. Applications include the measurement of endogenous nitric oxide (NO) in breath, such as for the monitoring or diagnosis of asthma and other pulmonary conditions.

Sensor having a thin-film inhibition layer

A tunable nanoscale resonator has potential applications in precise mass, force, position, and frequency measurement. One embodiment of this device consists of a specially prepared multiwalled carbon nanotube (MWNT) suspended between a metal electrode and a mobile, piezoelectrically controlled contact. By harnessing a unique telescoping ability of MWNTs, one may controllably slide an inner nanotube core from its outer nanotube casing, effectively changing its length and thereby changing the tuning of its resonance frequency. Resonant energy transfer may be used with a nanoresonator to detect molecules at a specific target oscillation frequency, without the use of a chemical label, to provide label-free chemical species detection.

Tunable multiwalled nanotube resonator

Methods by which the growth of a nanostructure may be precisely controlled by an electrical current are described here. In one embodiment, an interior nanostructure is grown to a predetermined geometry inside another nanostructure, which serves as a reaction chamber. The growth is effected by a catalytic agent loaded with feedstock for the interior nanostructure. Another embodiment allows a preexisting marginal quality nanostructure to be zone refined into a higher-quality nanostructure by driving a catalytic agent down a controlled length of the nanostructure with an electric current. In both embodiments, the speed of nanostructure formation is adjustable, and the growth may be stopped and restarted at will. The catalytic agent may be doped or undoped to produce semiconductor effects, and the bead may be removed via acid etching.

Growing community of inventors

Albany, CA, United States of America

William E Mickelson