UniLB
Dr Sara Ronca working in her lab
Problems with overheating mobile phones could be reduced significantly thanks to a plastic being developed by Loughborough University scientists.
The material is ultra-high molecular-weight polyethylene (UHMWPE), which is used to make a variety of products, from prostheses to body armour.
The plastic, unlike the ones currently used in mobile phone covers, dissipates heat created by the lithium batteries and reduces the likelihood of injury to the owners.
Dr Sara Ronca, the principal investigator for the research into the plastic, said: “The current plastic cases do not dissipate heat and have been known to get too hot, with phones doing strange things.”
Dr Ronca said the new plastic is “vital” because the drive in electronics towards miniaturisation has increased the need for smart materials than can cope with things like heat dissipation.
It could be a major boost for manufacturers of all kinds of electronic devices, says the University, such as computers, electric motors and generators, solar panels, batteries and heat exchangers in power generation.
The plastic can be used as a heat sink in computers as a replacement for metals, which are expensive, heavy and also conduct electricity, and composite materials that are more expensive and harder to recycle because of the fillers they contain.
UHMWPE is not normally good at conducting heat, but Dr Ronca has developed a method of synthesising and processing it so that it does.
She said: “We know that it works, we know it is thermally conductive, because we already have the data. What we have to do now is find out how we can tailor the material for any industrial application.”
Dr Ronca, from the Department of Materials, is building on work started by Professor Sanjay Rastogi.
She has received a £98,000 grant from the Engineering and Physical Sciences Research Council (EPSRC) for the two year project whose aim is to get the plastic ready for industry, with the participation in kind of Teijin Aramid, a company from the Netherlands.
Professor Rastogi and Dr Ronca have developed a synthetic/processing strategy that allows achieving less entangled and highly aligned chains able to promote heat transfer by something called lattice vibration.
She said: “We have devised a synthetic strategy that enables us to directly obtain UHMWPE with a reduced number of entanglements.
“It is easier to process this material in a way that chains are extended and nicely aligned.
“When you get this type of structure the polymer is not conductive electrically but it can conduct thermal energy by lattice movement.
“We have demonstrated that this material can be easily processed, without the need for any solvent, to give tapes and filaments with high chain alignment.
“The question is, can we get a material that has different thermal conductivities according to the polymer’s molecular characteristics?
“And can we tailor thermal conductivity by tailoring the material properties?
“The results from the project will enable us to realise a lightweight, cheap, easy to process and to recycle material where the thermal conductivity can be tuned in a range of useful values by suitable modifications of the synthetic processing steps.”