Want to carry hydrogen in your pocket? The latest invention out of Waseda University makes it possible.

A team of researchers in Japan have developed a thin, flexible polymer sheet that safely and efficiently absorbs and stores hydrogen. Even when saturated with hydrogen, the polymer is safe to touch.

Few people need to carry hydrogen in their pocket, but with the gas promising to replace more harmful fossil fuels, new and improved hydrogen storage technologies are much needed.

The latest invention allows the capture of hydrogen molecules using electrolytic hydrogenation in room-temperature water. An aqueous iridium catalyst triggers the thin polymer to release the hydrogen at a temperature of 80 degrees Celsius. Tests prove the polymer sheet can absorb and release hydrogen for several cycles without significant deterioration.

Previously developed hydrogenation technologies require high pressure and temperature for successful absorption and storage, creating safety issues. The ketone, or fluorenone, polymer avoids issues of flammability and explosiveness.

"The easy handling and moldable polymers could suggest a pocketable hydrogen carrier," researchers wrote in their new paper on the discovery -- published this week in the journal Nature.