Multi-touch technology provides a means of actuation directly integrated into the display surface. Although these displays allow direct interaction, this interaction lacks the three-dimensional tangibility of solid objects, as representation still occurs on a two dimensional surface. At the same time, tangible computing creates a physical link between real-world objects and the virtual domain, but uses solid objects that are not transformed during the interaction. The qualities which one technology possesses the other lacks. Ideally, an implementation that embodies the qualities of both methods of interaction seamlessly needs to be pursued.
In light of this need, we present a new methodology based on ferromagnetic fluids in which the user can have direct interaction (input/output) through a tangible and malleable interface. Using the physical qualities of ferromagnetic fluids in combination with capacitive, multi-touch technology, we are able to produce a tangible, malleable, 3D, multi-touch interface where actuation, representation and self-configuration occur through the tangible object (ferromagnetic fluid). Liquid Interfaces allows direct interaction through the ferromagnetic fluid, allowing the user to produce a 3D response. Combined with the ability to produce sound and light, the user can create musical sculptures interacting directly with the ferromagnetic fluid.