This design guide for [Project Lyta can help in checking how technological and design decisions relate to a common conceptual framework.

… This needs to be moulded into a proper shape, but here are some introductory notes

Before reading further, try this: take a sheet of paper or a thick fabric. Try touching something, or better someone through this primitive interface. What do you notice first? what makes it exciting to keep exploring?

• mlf/zzk: dynamics seems crucial. rapid changes in pressure and texture as well as temperature appeared more important than the size of surface displacement that would reveal the shape. If the shape protruded more, we were less focused on the action of touching, and more on rationally guessing what the shape might be….

A remote touch generator. An interface for touching on a distance.

• The most distributed human sense, by which pressure or traction exerted on the skin is recognized; the sense by which the properties of bodies are determined by contact; the tactile sense.
• The faculty of touch; “only sight and touch enable us to locate objects in the space around us”

But more importantly, we are interested in touch as action:

• To come in contact with; to hit or strike lightly against; to extend the hand, foot, or the like, so as to reach or rest on.
• To affect the senses or the sensibility of; to move; to melt; to soften
• To strike; to manipulate; to play on; as, to touch an instrument of music.
• To be in contact; to be in a state of junction, so that no space is between
• The act of touching, or the state of being touched; contact

• reality check
• intimacy
• awareness of the surrounding through tactile perception

Information about a surface, though the direct contact with the surface: )

• shape (in 2d and 3d)
• texture
• temperature
• humidity

DYNAMICS: The sense of touch is ultimately the sense of change, modification of the surface properties through time.

• sound
• change of colour that occurs through touching an alive or active material

• simulation of a direct contact with something that is remote:
  • a person on a distance in real time (interactive - one can not touch without being touched back by a real person)
  • recording of a person (non real time, passive)
  • computer generated (real time simulation, interactive)
• giving the impression of touching something 'other' than the physical surface

-⇒ can we sense the difference between touching a real person and touching a computer simulation?

Ideally, we would have actuation of all of the following properties of the surface:

¥	Texture, through tactile stimuli (smoothness/roughness, slipperiness/stickyness)
¥	Shape, through surface displacement/force feedback (hardness/softness, thickness, flexibility)
¥	Temperature, through local change of temperature (hot/cold)
¥	Humidity, through change of local surface humidity (wet/dry)

and to add to the synaesthetic experience, we can actuate:

¥	Colour, through local change of the light frequency (visual image of the touched object)
¥	Sound, through the sonification of the texture data (additional information about the textural structure of the surface)

However, we will most probably have to discard actuating humidity and temperature because of the current state of the art in understanding these properties. Sound will not be used due to the 'noisiness' of the space where the installation will be placed in Phaeno.

This leaves the actuation of texture and shape as two modes to be combined for representation of remote touch. Colour could be added to enchance the visual impact of the touch, as well as to add to the experience of the people who are not touching the surface (considering that it is a public space…).

• Pressure
• Stretch
• Geometric Deformation
• Resistance

Tactile feedback (electrocutaneous/vibrotactile: pneumatic, piezo-electric, SMA/SMP/SMC, EAP)

• resistance
• pressure
• gradient
• resolution
• frequency (bandwidth)
• speed

Force feedback (pneumatic, electromagnetic, piezo-electric, SMA/SMP/SMC, EAP, magnetostrictive, hydraulic)

• displacement gradient
• resolution
• speed
• distance range

Chromatic actuation

• brightness
• resolution
• density
• spectral gradient

• wish to interact through touch (not remain a distant observer)
• intimacy and excitement by simulating direct contact with remote objects and people
• exploration of tactile media (surface dialogue, tactile language)

How we can possibly do all this? see Project Lyta Materials Research, Project Lyta Design Research, Active Materials, Haptic Feedback…