Infofuses are strips of the flammable nitrocellulose patterned with thermally emissive salts that produce different colours when they burn. These can be used to transmit alphanumeric messages
Credit: George Whiteside
SYDNEY: Pulses of light from thin, burning fuses can transmit information in a similar way to Morse code, but with no electricity, thanks to a new invention.
Combustion-powered 'infofuses' unite the fields of chemistry and information technology, creating a new discipline, 'infochemistry', detailed this week in the Proceedings of the National Academy of Sciences.
Infochemistry could be useful in application where electricity is not available, such as for communication underwater, according to lead researcher George Whitesides of Harvard University in Boston, USA.
Military applications
Infofuses could also have military applications, allowing soldiers in the field to communicate with each other without electricity – a bit like a high tech smoke signal, he said.
Inspired by the way DNA inside cells can be translated into meaningful information, Whitesides' team set to work to invent an artificial chemical coding system. "We wanted to find methods of doing 'communication and computation' without using computers and electricity" he said.
Much like a fireworks display, infofuses give off a patterned sequence of coloured flashes as they burn – but on a much smaller, less explosive scale.
To achieve this, the researchers used an inkjet printer to deposit tiny dots of metal salts onto strips of highly flammable nitrocellulose. Once set alight, a flamefront moves along the fuse, emitting a flash of coloured light whenever it encounters a metal dot. Messages can be read with the naked eye, or captured using a camera.
The colour of the flash depends on the type of metal dot encountered. By using the metals lithium, rubidium, and caesium – corresponding to three different colours – and two flashes to represent each character, the researchers were able to encode up to 49 bits of information.
This allowed them to represent all the letters of the alphabet; the digits one to nine; and some special characters.
Look Mum, no electricity!
"Look mum no electricty" said the first infofuse message, transmitted over a distance of 30 metres during daylight. This message took just over two seconds to send, although future, thinner fuses will be faster, according to the researchers.
Chemical engineer Amilra de Silva, from Queen's University in Belfast, Northern Ireland, was impressed. He noted that slow-burning fuses have been used since ancient times to encode information, particularly time.
"The authors have combined these old phenomena to contribute to the field of chemical information handling … this is a significant piece of work" he said.
Whitesides' team are also developing electricity-free communication systems using bubbles and microchemical lasers.
