Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Faster and more sensitive electronics thanks to compact cooling

02.04.2008
Electronics work better under cold conditions (-150oC): with less thermal noise, detectors are more sensitive and low-noise amplifiers reduce noise further.

Furthermore, the speed and reliability are increased. Dutch-sponsored researcher Srinivas Vanapalli has investigated the possibilities for the extreme cooling of electronic components at a chip level.

Besides research into extremely small structures, Vanapalli has constructed a proof-of-principle cooler, which despite the smaller dimensions, cools more effectively than conventional coolers and has therefore aroused commercial interest. Vanapalli carried out his successful research at the University of Twente, partly in cooperation with the ‘National Institute of Standard and Technology’ in Boulders, US.

He focused on miniaturising regenerative coolers. These are coolers that make use of the oscillating compression and expansion of a working gas. Two factors proved to be critical in the miniaturisation of these coolers: the cycle frequency had to be increased as well as the average pressure of the gas in the system. Both are necessary to ensure that the miniaturised system has sufficient cooling capacity.

Vanapalli constructed a cooler with a frequency of 120 Hz. This cooler was approximately three times smaller than conventional (50 Hz) coolers, yet nevertheless had a higher cooling output and cooled down the smaller dimensions much faster. The cooler was realised in close cooperation with the ‘National Institute of Standard and Technology’ in Boulder, US. Thales Cryogenics in Eindhoven has expressed a serious interest in this development, which is directly applicable to their products.

Vanapalli carried out a significant part of his research on even smaller and consequently even higher frequency coolers. This mainly concerned the balance between heat exchange and pressure drop in the micro-channels of the cooler. A good heat exchange requires many small gas channels but then the pressure loss is unacceptably high. Consequently a compromise must be sought. Test structures were etched in silicon with a typical width of 20 µm and a height of 200 µm. Theoretical models were found to accurately describe the pressure losses caused by this type of structures.

An important step towards a high-frequency microcooler is Vanapalli's research on a 1 kHz compressor that works on the basis of a metal membrane moved by a piezo stack.

Regenerative coolers
Regenerative coolers compress a working gas, usually helium, cyclically. In a regenerator, incoming hot gas transfers heat to the matrix of the regenerator, where the heat is stored for a half cycle in the heat capacity of the matrix. In the second half of the cycle the returning cold gas flowing in the opposite direction through the same channel, picks up heat from the matrix and returns the matrix to its original temperature before the cycle is repeated. At equilibrium, one end of the regenerator is at room temperature while the other end is at the cold temperature.

Srinivas Vanapalli | EurekAlert!
Further information:
http://www.utwente.nl

More articles from Power and Electrical Engineering:

nachricht Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

Metallic nanoparticles will help to determine the percentage of volatile compounds

20.10.2017 | Materials Sciences

Shallow soils promote savannas in South America

20.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>