NANOCOOLING
UPDATED DECEMBER 10, 2005
RTI - Rama Venkatasubramanian - Nextreme Thermal Solutions
Breakthroughs in Thermoelectrics
Link to article on Rama Venkatasubramanian
Link to article on Breakthroughs in Thermoelectrics
Link to article on Cold Cathode Emitters
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email address:[email protected]

Cool Operator
Interview by Karen Auguston Field
Design News
June 16, 2003
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Superlattice Thermoelectric Technology - February 18, 2004
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More efficient and reliable refrigerators and air conditioners a step closer to reality - March, 2003
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Nano-structured Thermoelectric Materials Nano-structured Thermoelectric Materials
8th Diesel Engine Emissions Reduction Conference
Loews Coronado Bay Resort
San Diego, CA
August 25, 2002
Link to PDF PowerPoint file

Superlattices Chill Hot Processors
By Henry S. Kenyon
Tiny heat pumps offer rapid cooling for electronics, fiber optics.
Re commercialization
Supported by DARPA and ONR funding, the institute has developed several prototype devices
to prove the technology works, Venkatasubramanian says. One technology demonstrator built
by RTI scientists allows a user to observe a temperature drop or increase when he or she presses
a switch or reverses the current. The prototype can generate a cooling of 32 degrees Celsius at
room temperature.
Beyond this example, the institute is moving quickly to develop the technology for use in existing
devices. Solid-state cooling/heating systems for fiber optics and wafer-scale cooling for microchips
are the alloy�s most immediate applications. Venkatasubramanian predicts that RTI may have a
product ready within a year.
Because RTI is a nonprofit research organization, it is spinning off a company to make commercial
prototypes. This new firm will conduct prototype fabrication runs and develop a manufacturing plan
for producing large volumes of thermoelectric devices.
He notes that some 35 companies are interested
in the technology.

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nanoElectronics & Photonics Forum Conference
Full Day Event - Palo Alto, CA - April 15, 2004
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Thin-film thermoelectric devices with
high room-temperature figures of merit
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US PATENTS
6,300,150
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6,505,468
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6,662,570
Link

6,722,140
Link

Nextreme Thermal Solutions
Nextreme Thermal Solutions Raises $8 Million in Series A Financing
RTI International spin-off to commercialize breakthrough thermoelectric material
Link to Nextreme
Link to PR
SCIENCE/TECHNOLOGY April 3, 2000 - Cold Cathode Emitters

PLAYING IT COOL
In addition to the thermionic work, scientists are studying a similar technology based on
so-called
cold cathode emitters. These are created from micrometer-sized, pyramid-shaped
silicon structures arranged on a silicon platform in an array containing thousands per square
centimeter. "Because they are pointed, you get a very strong electric field right at the point,
so they emit electrons even when they are cold," Vining says. These devices have been around
for years, he notes, but researchers are just beginning to consider their use in cooling applications.
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ICURIE LAB HOLDINGS - The Power of Nanotechnology at Work Today
Nano-fluidic cooling channels
Link to iCurie web site

Patents
Link to espacenet for patents list
Link to US Patent 6,698,502
Sandia - Micro cooling channels for microprocessors
A small amount of a cooling fluid--barely a few drops--is injected between the plates;
then the edges are sealed. The coolant directly underneath the microchip heats up and
evaporates. When the vapor reaches cooler areas, it condenses. Capillary pressure then
draws the liquid coolant back to hotter regions where the process repeats. The evaporation
and condensation cycle distributes the heat evenly though the substrate.
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Tuominen, University of Massachusetts at Amherst
US Patent Filing 20020158342 Oct. 31, 2002

FIG. 9 is a diagram of a single-stage thermoelectric cooler which can be made according
to the methods described herein. The substrate has electrodes pre-patterned in or on its
surface. A patterned diblock copolymer layer is created on the substrate, as described herein.
Again, the matrix component of the copolymer is deleted in FIG. 9 for clarity. Nanowires of
two types are deposited by programmed electrodeposition. In the depicted example, "n-type"
nanowires, made from "n-type" materials, well known in the art, are deposited at one electrode,
and "p-type" nanowires, made from "p-type" materials, also well known in the art, are deposited
at another electrode. A top-layer metal interconnect is then deposited electrochemically. The
device operates through the application of current through the device, so that the top plate becomes
cold and the electrodes and substrate become warm. The top plate can be used as a heat sink for
use in electronic devices, for example. Multistage coolers can also be made by this fabrication
method. Heating devices are also made possible by the simple adaptation of the device for such purposes.
Link to US patent filing
RTI - Rama Venkatasubramanian, Anser Tech
RTI INTERNATIONAL SPINS OUT ANOTHER HIGH-TECH VENTURE
RTI is commercializing technology developed by a group of researchers led by
Rama Venkatasubramanian.
The Triangle Business Journal reported last week that the new company is called Anser Tech and
has already raised $3.5 million in venture funding, including investment from The Aurora Funds in Durham.
Venkatasubramanian will join the new company as chief technology officer, RTI said. In all, about 20
RTI employees will also work with the startup.
Link to article
Link to article 2
Link to anser-tech.com
NALIN KUMAR, United States Patent Application 20050016575
(PENN STATE and UHV Technologies Inc.)
(With a potential NNPP invovement through USP 5,399,238 Kumar,  March 21, 1995 )
95% Carnot efficiency

January 27, 2005, Priority Date June 13, 2003
Field emission based thermoelectric device
What we claim as our invention is:
1. A device comprising an assembly containing a thermoelectric device and one or more other devices
where these other devices act as electrically conducting but thermally insulating elements.
2. A device of claim 1, where the electrically conducting but thermally insulating elements are field emission devices.

The tips can be made from either metals such as molybdenum, tungsten, nickel and copper, from semiconductors
such as silicon, gallium arsenide and gemanium, or from other materials such as graphite, diamond,
carbon nanotubes,
or from a combination thereof.

[0044] When silicon tips are used, it is possible to obtain large emitted electron current density from these tips at
an electric field of 0.5 MV/m (megavolts per meter). Using a device gap of 100 nm and a modest emitted current
density of 1 ampere per square cm, we obtain a cooling capacity of almost 1 watt per square cm. Since the applied
voltage is only 0.05 volts, the efficiency is almost 95% of the Carnot efficiency. This is much higher than 5-10%
for prior art thermoelectric coolers and 40-50% for the mechanical coolers.

[0042] Another embodiment of the present invention is shown in FIG. 6, which is obtained by removing the grid 302
in the device shown in FIG. 3. The device structure depicted schematically is a two electrode configuration, forming
a diode. It consists of two metal or ceramic plates 601 and 602 that form the cathode and the anode of the device,
respectively. The cathode plate is coated with an electrically conducting layer 603, followed by fabrication of micro-tips
609, made from either metal,
carbon nanotubes or silicon. One method for making these types of micro-tips has been
described earlier by Kumar in U.S. Pat. No. 5,399,238[NNPP assigned].
Again, the plates are separated by a suitable
gap by using electrically and thermally insulating spacers 605, followed by sealing and evacuation of the device. In
addition to the absence of the grid, another difference between diode and triode devices is the fact that the
anode-cathode gap is very small in the diode devices, on the order of 100-1,000 nanometers (nm). While this is small
as compared to the gap in triode devices, the diode gap is still very large as compared to 5-50 nm required by prior art
diode type cooler devices taught by Edelson and Cox.

Link to US 20050016575
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Link to Kumar USP 5,399,238 (NNPP)
Link to Kumar USP 5,312,514 (NNPP)

A HIGHLY EFFICIENT THERMOELECTRIC CRYOCOOLER
Nalin Kumar, UHV Technologies, Inc.

Link to SBIR grant to UHV Technologies

Emissive and Cooling Properties of Carbon Based Materials for Microelectronics
N. M. Miskovsky, P. H. Cutler, A. Mayera, and Peter B. Lerner
Department of Physics 104 Davey Laboratory The Pennsylvania State University University Park, PA 16802
ABSTRACT
Among carbon-based materials, diamond and nanotubes exhibit field emission characteristics, which can be very
useful for applications.
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Starting small, thinking big

City-funded incubator aims to foster new technology firms
Higgs also ran into Nalin Kumar, president of UHV Technologies in New Jersey, while giving a speech on
small-business innovation research. Higgs persuaded the molecular biologist to relocate to Tech Fort Worth.
Kumar's small operation had already received a $1 million Defense Department contract to continue development
of its nanotechnology.

Link to newspaper article on UHV Technologies relocating to Fort Worth dated Jul. 19, 2004
NANOTHERMIONIC LINK
Purdue, Jaeseon Lee, Issam Mudawar
Miniature cooling device will have military, computer uses
Two-phase flow in high-heat-flux micro-channel heat sink for refrigeration cooling applications
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