Chase Research Cryogenics specialises in the design and manufacture of sub-Kelvin cryocoolers and heat switches. The business was originally formed in Sheffield in 1993 and its primary focus at that time was on creating sub-Kelvin cryocoolers for use in astronomy. The business was incorporated as Chase Research Cryogenics ten years later and the emphasis today is on creating innovative custom-designed products for clients operating in a wide range of high-technology fields requiring ultra-low temperatures.

We were approached by Chase Research Cryogenics because the company had encountered problems with a particular product that was in development. The task presented to us was to explore whether or not there were any alternative materials that could potentially be used in an effort to rectify those problems.

‘We had problems with the performance of a miniature dilution refrigerator product that we were developing and wanted to explore some alternative materials that might provide solutions,’ explained Dr Lee Caroline Kenny, who is CEO of Chase Research Cryogenics. ‘As a small business, we don’t have free access to scientific literature, which seriously cramps our R&D effort. Working with the university enabled us to consult experts in materials science and to access the latest research literature on materials of interest.’

Dr Kenny continued: ‘We asked the University to review porous materials with a view to identifying potential candidates for two applications, one being the fabrication of a cryogenic superleak, and the second being the fabrication of improved cryogenic heat exchangers.’

Materials science researchers at Sheffield Hallam University conducted a full literature review into potential porous materials or new technologies that the company might find useful for the stated applications. This involved carrying out a comprehensive search of the available literature, identifying all papers of relevance, and reviewing those papers pertaining to porous materials in an effort to determine which, if any, could potentially be suitable for use in the fabrication of a cryogenic superleak or heat exchanger.

In addition to this comprehensive literature search and review, we also undertook testing work on several samples of porous silver and porous copper which had been produced by the company. This involved examining the microstructure of the samples to determine their porosity, and to provide a detailed report on our findings.

Our literature search and review enabled us to identify a number of materials that were not suitable for further investigation for the applications being proposed, as well as some that could be potentially viable, but not without first finding solutions to additional problems. The review also concluded that very little research had been carried out on novel materials as far as investigation into their cryogenic properties was concerned.

After testing the metal samples provided, we were able to provide the company with a precise and detailed explanation of our findings concerning their relative levels of porosity and associated morphologies.

After reviewing our findings, Chase Research Cryogenics concluded that while several of the novel materials looked very promising, much more work would be needed before they could be adopted for cryogenic use. Whilst that might not have been the preferred outcome, it was one which helped the company to save time and money that might otherwise have been spent pursuing a less effective course of action. As a result, the company was ultimately pleased with the work that was carried out on its behalf.

‘Every part of the work done was very useful to the company, primarily because it ruled out many materials, and highlighted challenges that would need to be overcome with others,’ said Dr Kenny. ‘The literature review showed that there is very little research work being done on the cryogenic properties of novel materials, in particular those being produced by additive manufacturing. As a company, this basic research is not something that we ourselves can undertake, however we hope that it might be of interest to a university as it could lead to significant advances in cryogenic engineering in future.’

This case study demonstrates how working with our team of experts here at the Materials and Engineering Research Institute can be helpful even when the eventual findings of our work are not as fruitful as initially hoped. As Dr Kenny said: ‘I think our company is not typical as we spend around 50% of our time on R&D and we already work with universities. Where it really did add value for us however was in having access to experts in materials science, i.e. outside our own field, who were able to identify and explore synergies across disciplines.’

For further information please contact 0114 225 3500 or meri@shu.ac.uk