If a thief is not to attempt to manipulate a security system, the most important thing is that it should be unobtrusive and difficult to access. For this reason, a group of Swiss scientists have developed a keypad with a completely transparent access code.
Created through a collaboration between the Empa research institute, EPFL and the Paul Scherrer Institute, the prototype device consists of a thin, transparent polymer substrate, on which are ink-jet printed numeric buttons and circuits made of transparent ink. The ink contains nano particles of indium and tin oxide and is electrically conductive.
The production process involves dyeing the film blue once the ink has been applied. A high-energy light irradiation process is then used to synthesize the buttons and circuitry – this process makes the ink considerably more conductive than before.
The blue coloration helps the substrate absorb the light, but then this eventually fades as part of the irradiation process, leaving the film transparent again, reports New Atlas.
The finished product can adhere to any surface near a door, safe, or other place with restricted access – as long as it has a power source available. As with traditional systems, typing in the correct code will cause the door to open.
Only authorized people should know where the keypad is located and which buttons to press.
Since the buttons are not visible, an electronic display, located nearby, should help the process as it shows users which numbers are currently being selected.
