Palpable City is a location aware garment that allows walkers to feel the spatial form of the urban grid as vibro-tactile rhythms on their body. The rhythms of the city space are parameterized by local conditions as the walker encounters them, reflecting the influence of time, light, temperature and humidity on the experience of space. The tactile space created can only be explored by moving through it.

The system consists of a GPS and a torso tactile display that communicates tactile textures related to the spatial form of the environment. Vibrotactile actuators are used to produce sensory saltation. Sensory saltation occurs across the senses resulting in the perception of apparent motion.

Three mechanical stimulators are placed on the forearm. The stimulator closest to the wrist delivers 3 short pulses, followed by 3 more at the middle stimulator, then 3 more at the last one. Instead of perceiving 3 pulses at each of the stimulator sites, the observer perceives that all of the pulses are distributed with approximately uniform spacing from the site of the first stimulator to the site of the third. The sensation is described as if a tiny rabbit was hopping up the arm from wrist to elbow.

Using variations in these parameters, a group of concepts which can be perceived through the tactile sense emerged. For example, a single point can be perceived as a direction. Taking advantage of sensory saltation, lines can be perceived, as can their length, straightness, spatial distribution and smoothness. More recent research suggests planes and 3D forms can be perceived. Tactors on the body can create a 360 degree “field of touch” where lines and forms can be perceived not just on the surface of the body, but through the body.

A work by Eric Conrad. Presentation at Subtle Technologies, June 1-4 2006, Toronto, Canada.

Related: The city as a musical interface.