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 Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht Researchers develop environmentally friendly soy air filter
16.01.2017 | Washington State University

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: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

How gut bacteria can make us ill

18.01.2017 | Life Sciences

On track to heal leukaemia

18.01.2017 | Health and Medicine

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>