Researchers from Singapore have created a coating material making objects invisible by blocking their thermal radiation.
The invisibility cloak, described in recent issues of two prominent journals – Advanced Materials and Physical Research Letters – relies on the so-called thermotic materials, which provide thermal camouflage by suppressing the object’s natural heat radiation.
“This is the first time that such a cloak has been proven to work effectively, based on thermotics,” said Qiu Chengwei, the leader of the engineering team from the National University of Singapore. “Our success means that now we have a cloaking technology that is cost-effective and easily scalable and applicable to even bigger objects such as soldiers on night missions.”
The materials used to achieve the seeming invisibility were mostly bulk natural materials not requiring extensive processing. Using those materials, the team managed to control the thermal illusions’ shapes, material properties, distributions, as well as locations
“This drastically overcomes practical and challenging limitations of metamaterials which are not found in nature and hence would require complicated and complex design to imbue them with special properties,” Chengwei said. “Our new technology has also overcome limitations like narrow bandwidth and polarisation-dependence.”
The team believes the technology, exhibiting excellent thermodynamic performance, is ready to be commercialised, with the military being the most likely first customer.
If modified, the technology could also be used to control heat in highly packed electronic circuits, interconnectors and batteries.
The research has introduced a new dimension to the emerging field of “phononics”, which is the control and manipulation of heat flow with phonons – particles which transmit heat within solid materials.