We've got 3DTVs, surround-sound speakers and motion-scanning video game controllers, but there's one thing still missing from a truly immersive virtual-reality experience: smell.
Now, researchers at the University of California, San Diego and Samsung Electronics in Suwon, South Korea say they've come up with a device that will get us all sniffing in our living rooms.
Attempts to build virtual scents are nothing new, but the scientists behind this latest device say that previous techniques don't allow enough control and are too bulky to scale down for home use. Their new approach, published this week in the journal Angewandte Chemie, traps odorous gases inside small cells made from polydimethylsiloxane (PDMS), the material which gives Silly Putty its unusual properties. Each cell has a small hole in the top which opens when the gas inside is heated, releasing the desired odour.
The researchers arranged a number of these cells into a grid, with a wire piercing each row and column. Running an electrical current through these wires causes the gases in that row or column to heat up, but crucially a cell will only open when heated by two crossing wires at the same time. This system allows the researchers to select a particular cell from the grid just by heating the appropriate wires.
Such finely-tuned control means the device can be switched on or off in just 40 seconds, the time it takes for the gases to heat up or cool down - previous techniques suffered from smells that would hang around too long. To demonstrate the potential for quickly switching smells, the researchers tested the release of two perfumes: Live by Jennifer Lopez and Passion by Elizabeth Taylor. Testers were able to smell the difference with just a 2-minute gap between the release of each scent.