Air is made of two spherical-shaped lamps. It uses light as a communication channel and it is made of two lamps which turn on when you lightly touch them, and this makes visible the moment in which the partners in a couple are thinking about each other.
Source: Ogawa, H., Ando, N., and Onodera, S. 2005. SmallConnection. In Proceedings of the 13th Annual ACM International Conference on Multimedia (MULTIMEDIA’05). ACM Press, 1073–1074.
http://www.digicult.it/digimag/issue-067/new-media-art-in-japan-hideaki-ogawa-and-the-device-art/