A tiny slider that tickles a user’s thumb with eight piezoelectric bristles could revolutionize how we interact with our devices, if someone ever figures out how to commercialize the technology. Called the THMB interface, its current application is limited to giving users haptic feedback as they scroll through a long list of items. It’s sort of like the original iPod’s scroll wheel, only better.
The latest research (pdf) on an improved version of the THMB interface (it now refreshes 800 times a second) shows that it reduces the number of times users had to glance at the screen of an iPod-like device by 28 percent.
The THMB slider has three modes: neutral, advancing one item at a time, and rapid scrolling, in both an up and a down direction. Current moving across its piezoelectric bristles causes them to move back and forth, creating the illusion of motion across a user’s thumb-pad.
It’s no surprise that an interface like this can deliver significant amounts of information: fingertips have some of the highest densities of sensory neurons on the body. Humans can detect miniscule bumps with their pads of their fingers. Think of the last time you ran your fingers across a roll of tape to find its otherwise-invisible beginning.
What’s interesting is that, despite work on haptic interfaces dating back to the 1960s, when engineers thought they could help inform fighter pilots when their planes were about to stall, they have yet to penetrate mass market consumer devices.