NJIT develops ‘smart’ label technology for military use

The technology, referred to as a ‘thermal-indicating composition’, was commissioned and funded by the US Army Armament Research Development and Engineering Center (ARDEC) in response to dangerous conditions in the desert during the war in Iraq, for example, where soldiers reported temperatures near munitions that had sometimes exceeded 190 degrees F, far in excess of the design limits of munitions.

It is applied as a coating or a mark on packaging, with the material turning different shades of color from blue to red in response to a range of temperatures, beginning at about 95 degrees F. It was awarded a US patent in May of this year.

Zafar Iqbal, a research professor in NJIT’s Department of Chemistry and Environmental Science, led the team that has developed this technology, with his current research rooted in earlier work at Honeywell, then Allied Corp., leading to a smart coating embedded with color-sensitive materials that indicates how long a substance had been exposed to temperatures high enough to compromise its functionality. This time-temperature device has been widely used by the World Health Organization, for example, on vaccine packaging labels.

Time-temperature coding is also important for munitions, which can be stored for many years and transported long distances. Until now, there has been no cost-effective means for identifying when munitions have experienced critical exposures, including over a period of several days. Thermal stabilizers incorporated in weapon containers can be depleted by extended exposure to high temperatures.

Iqbal said: ‘It would have been helpful to have had some sort of a calibrated temperature-triggered signal warning; “Don’t go near or pick up this shell!”.

‘We essentially modified commercial paints and introduced nanotechnology-based concepts to tailor the trigger temperatures.’

The technology has potentially wider applications as well, including as a temperature indicator for factory machines and household appliances, and tools signalling they have become dangerously hot, or as a warning to firefighters of the intensity of a fire on the other side of a door coated with the thermal paint.

The patent is jointly owned by NJIT and the US Army, with NJIT working to commercialize the technology. Iqbal’s laboratory is starting to develop inks related to the paints that can be applied by inkjet printers, while Iqbal himself is currently developing a related technology that would signal whether a product has been damaged by force, shock or exposure to dangerous chemicals, such as carcinogens or to radiation. This could be deployed in sports helmets used in American football, as an example, helping coaches to determine whether a player has received a damaging blow to the head.

‘A smart coded coating is like a smart skin – it will provide a visual or sensing signal to tell you if there is a problem,’ Iqbal said.