forms affect motion perception and control. A very significant perceptual shift can occur with a change in material and forms—a jerky disjointed motion of a series of mechanical motors can be embedded in a soft padded exterior and the perceived quality of motion can be inversed to a smooth oscillation. Understanding the material affordances, their interaction with the user and other objects, environmental light and sound is crucial in designing kinetic interactions.

Kinetic Memory and Temporality. While computational control allows actuated systems to provide real-time physical feedback, it also offers the capability to record, replay, and manipulate kinetic data as if it were any other kind of computational data. We refer to such data as kinetic memory, an idea introduced earlier by Topobo [ 11]. The concept of kinetic memory opens new and unexplored capabilities for KOIs; for example, objects can fast-forward or slow down motion sequences, move backward or forward in time; or the objects can “memorize” their shape history and share them with other objects.

Repeatability and Exactness. We can easily distinguish artificial motion because of its exact repeatability. In designing kinetic interactions, repeatable exactness is the simplest form of control state, and in many behaviors it is easily identifiable. Introducing a level of variation in kinetic interfaces or perhaps even “noise” can add a degree of an organic natural feeling, usually missing from direct digital actuator control.

Granularity and Emergence. During the period of 1772–1779, Swedish engineer Kristofer Polhem created a series of small wooden objects describing basic mechanical elements for motion design: a mechanical alphabet. It consisted of 80 letters each demonstrating the simple movement that is contained in a machine, for example, translating rotary movement into reciprocating movement. If this principle of dissecting form and mechanics into single elements—kinetic phrases—is combined with contemporary digital control structures, new materials, and actuators, it becomes possible to imagine a system where a kinetic behavior could be designed both concretely and formally. This would allow a designer to easily merge kinetic elements into user interfaces as well as everyday objects, living and working environments.

Inventing such basic “grains” of motion in kinetic interactions also brings up the issue of emergence. Emergence, defined as the process by which a set of simple rules determine complex pattern formation or behavior, creates systems that contain elements that are thoroughly comprehensible to understand individually (like ants in an ant colony), while it is difficult to understand the overall behavior of the system functioning with decentralized control. Designing for

emergence, KOIs may create systems that could someday reflect some of the complexity of living organisms.

As we move into the 21st century, it is clear that our relationship with motion needs to be reconsidered. The new class of emerging Kinetic Organic Interfaces is a step toward creating that change. The rapid development of new technologies, such as piezo motors and plastic actuators polymers, will potentially allow for creating efficient and inexpensive interfaces that can be used in applications for communication, information presentation, style, and decoration, as well as many others. Developing such applications requires stepping outside of the boundaries of classic HCI domains and combining expertise from robotics, haptics, design, and architecture. The work in Kinetic Organic Interfaces is still in its infancy, and we consider this article as an invitation for discussion on the future of kinetic design in user interfaces and as stimulus for further research in this exciting and emerging area. ^c

 

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AMANDA PARKES ( [e-mail]) is a Ph.D. candidate in the Tangible Media Group at MIT.

IVAN POUPYREV ( [e-mail]) is a member of Sony Computer Science Labs, Inc., Tokyo, Japan.

HIROSHI ISHII ( [e-mail]) is the Muriel R. Cooper Professor of Media Arts and Sciences at the MIT Media Lab, Cambridge, MA, where he heads the Tangible Media Group and is co-director of the Things That Think consortium.

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