Isis fighters have managed to make their own thermal batteries for surface-to-air missiles and remote-controlled car bombs, according to a new report.
The batteries have been manufactured in a "university of jihad" in the de facto capital of Isis (Islamic State), Raqqa, according to videos shown to Sky News.
Their development would be highly significant. While the group has captured large quantities of old missiles, few have been put to use as their batteries had decayed.
Isis have been pushed back in recent months in both Syria and Iraq thanks to their inability to strike back at air attacks from the Western allies, and now from Russian jets.
Coalition jets could now theoretically be at risk, though the most modern Western fighters are probably beyond the threat posed by older surface-to-air missiles of the sort owned by the Syrian Army, which Isis would have taken.
Of more concern might be the threat to civilian aircraft, if Isis managed to smuggle such weapons or batteries to operatives around the world - or the instructions on how to make them.
The threat to passenger planes from jihadists has been a constant concern of airlines in recent years, especially since the fall of Colonel Muammar Gaddafi in Libya.
Military experts at the time estimated that 20,000 surface-to-air missiles had gone missing from his stocks in the chaos that followed the civil war. But many of these were also out-of-date.
The new video material was handed to Sky News by the non-Isis rebels of the Free Syrian Army, who found it on an Isis fighter.
They seized him as he passed through their territory apparently on the way to Turkey.
They were apparently unaware of the exact nature of its contents. But when put together, it showed a training school in Raqqa where Isis-sponsored scientists developed new products.
Besides the missile battery, it also showed experiments with remote-controlled car bombs "driven" by dummies. The dummies have internal heat mechanisms that allow them to mimic the "scan signature" of human beings.
The video may have been intended to pass on to Isis trainers operating abroad, it is suggested.
Major Chris Hunter, a former British special forces bomb technician, is quoted in the report as saying the material was "shocking".
"With this training footage it's very clearly purely designed to pass on information - to pass on the progress in the research and development areas," he says. "It gives us a very good insight into where they are now, what they're aspiring to do and crucially the diversity of the types of threats we might face."