For many of us, the most memorable bits of school chemistry classes were lessons where we ignited metal salts over a Bunsen burner to produce brightly coloured flames, from the lilac of potassium to the distinctive red of lithium. Now a group of chemists from Harvard University have found a way of using these colourful flames to transmit coded information.
Working in the lab of legendary chemist George Whitesides, Samuel Thomas III has developed the 'infofuse', a strip of flammable paper patterned with metal salts. As the strip burns, the metals change the colour of the flames, creating…