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Nanojunction Sensors for the Detection of chemical and Biological Species

DOE Grant Recipients

Arizona Technology Enterprises

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Technology Marketing SummaryCommercial applications of nanotechnology require reliable and cost-effective methods to mass-fabricate various nanostructured materials and devices. Atomic-scale contacts between metal electrodes have been created mechanically by breaking a fine metal wire and by separating two metal electrodes in contact. The breaking and separating are usually controlled by an apparatus involving stepping motor or piezoelectric transducer. The contacts fabricated by the mechanical methods cannot be removed from the apparatus, and they are, therefore, not suitable for most applications. A non-mechanical method that anodizes an aluminum wire locally with an atomic force microscope has been reported, but the use of the atomic force microscope makes it impossible for mass-production.DescriptionResearchers at ASU have invented a self-terminated method to fabricate atomic-scale contacts and molecular-scale gaps between metal electrodes. This method can quickly and reliably mass-produce large arrays of atomic-scale contacts and gaps for various applications, including chemical and biological sensors, magnetoresistive sensors and molecular electronic and optoelectronic devices. This invention can turn these applications into commercial products.Benefits•    High sensitivity
•    Low sample concentration detection
•    Fast response time
•    Low power consumption
•    Ease of integration into other microelectronics
•    Ability to mass manufacture
•    Miniaturization of sensors
Applications and Industries•    Fabrication of molecular sensors for use in chemical and biological applications
•    Capable of rapid detection of hydrogen molecules in a fuel cell or hydrogen-fueled system
•    Construction of heavy metal ion sensors for use of early detection of trace metal contaminants on site
•    Biosensor construction where a single molecular binding event is converted into an electrical signal. This is useful in a number of applications including, antigen detection, nucleic acid sequencing, food inspection and early warning systems for biodefense
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Date
Patent 6,737,286
Patent
6,737,286
Apparatus and method for fabricating arrays of atomic-scale contacts and gaps between electrodes and applications thereof
A method for forming atomic-scale contacts and atomic-scale gaps between two electrodes is disclosed. The method provides for applying a voltage between two electrodes in a circuit with a resistor. The applied voltage etches metal ions off one electrode and deposits the metal ions onto the second electrode. The metal ions are deposited on the sharpest point of the second electrode, causing the second electrode to grow towards the first electrode until an atomic-scale contact is formed. By increasing the magnitude of the resistor, the etching and deposition process will terminate prior to contact, forming an atomic-scale gap. The atomic-scale contacts and gaps formed according to this method are useful as a variety of nanosensors including chemical sensors, biosensors, hydrogen ion sensors, heavy metal ion sensors, magnetoresistive sensors, and molecular switches.
05/18/2004
Issued
Patent 7,132,837
Patent
7,132,837
System and method for measuring conductivity on molecular level
A conductivity measurement system measures conductivity of molecules. A substance to be measured is applied to the first and second electrodes. A potential is applied across the electrodes. A computer-controlled motion controller moves a first electrode relative to a second electrode in discrete steps. In a first step, the electrodes are brought together in physical contact to form a plurality of molecular junctions. The electrodes are separated by a first distance which breaks a first molecular junction. The electrodes are separated by a second distance which breaks a second molecular junction. A conductivity measure is taken at each step. The process of separating the electrodes continues until conductivity measure is zero. The conductivity of one molecule corresponds to a last non-zero conductivity measurement prior to a zero conductivity measurement.
11/07/2006
Issued
Patent 7,030,452
Patent
7,030,452
Apparatus and method for fabricating arrays of atomic-scale contacts and gaps between electrodes and applications thereof
A method for forming atomic-scale contacts and atomic-scale gaps between two electrodes is disclosed. The method provides for applying a voltage between two electrodes in a circuit with a resistor. The applied voltage etches metal ions off one electrode and deposits the metal ions onto the second electrode. The metal ions are deposited on the sharpest point of the second electrode, causing the second electrode to grow towards the first electrode until an atomic-scale contact is formed. By increasing the magnitude of the resistor, the etching and deposition process will terminate prior to contact, forming an atomic-scale gap. The atomic-scale contacts and gaps formed according to this method are useful as a variety of nanosensors including chemical sensors, biosensors, hydrogen ion sensors, heavy metal ion sensors, magnetoresistive sensors, and molecular switches.
04/18/2006
Issued
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
AzTE Case # M02-023 & M04-089DevelopmentAvailable03/13/201203/13/2012

Contact Arizona Technology Enterprises About This Technology

To: Arizona Technology EnterprisesJack Geltosky, PhD<JGELTOSKY@AZTE.COM>