Interactive Plant Growing
© 1992, Christa Sommerer & Laurent Mignonneau
1. Interactive Plant Growing – living plants as interface
One of the first interactive computer art installations to use a natural and intuitive interface instead of the then-common devices such as joysticks, mouse, trackers or other technical interfaces is our installation Interactive Plant Growing (1992) [1, 2]. In this system real plants are the interfaces and users can touch these real plants to create artificial plants on a computer screen.
In this installation, living plants function as the interface between the human user and the artwork. Using, for example, living plants as an interface not only provides a new, emotionally charged and unusual connection between computers and living beings but also poses the questions of what a plant is, how we perceive it, and how we interact with it when we touch it or approach it. Natural interfaces also circumvent the annoyance of wearing unpleasant devices before entering virtual space (= unencumbered interaction).
By touching or merely approaching the real plants, users engage in a dialog with the real plants in the installation. The electrical potential differences (voltage) between the user’s body and the real plant is captured by the plant and interpreted as electrical signals that determine how the corresponding virtual 3D plants (which look similar to the real plants) grow on the projection screen. By modifying the distance between the user’s hands and the plant, the user can stop, continue, deform and rotate the virtual plant, as well as develop new plants and new combinations of plants. As the growth algorithms are programmed to allow maximum flexibility by taking every voltage value from the user’s interaction into account, the resulting plants on screen are always new and different, creating a complex combined image that depends on the viewer-plant interaction and the voltage values generated by that user-plant interaction. When the users user modifies the hand distance towards the real plant, he/she generates voltage values that become higher the closer the hand is towards the plant. We use 5 different distance levels to control the rotation of the virtual plants, their color values, their place where they grow on screen as well as on/off growth value. The images presented show the final results of that interaction on the screen as a collective image of virtual plants that were grown by several users.
1.1. User experiences in Interactive Plant Growing
Users who experienced this system have often reported that they suddenly realized that plants are actually living beings and that they have been astonished that plants really “feel something.” When thus touching a real plant and seeing the effect of this touch translated into a graphical form on a screen, users are suddenly reminded of that immanent intuition they already had about plants.
1.2. Related projects
The main inspiration to this work came from a famous book called “The secret live of plants”  and our desire to design an interface that is living and doesn’t use visible technology. Buxton has long been one of the most prominent critiques of commercially available interfaces and their technocentric design and proposed a more human centric design .
Recently, in 2007, a trend towards intelligent ambiences and new forms of hybrid interfaces for ubiquitous computing systems and intelligent embedded systems has emerged in HCI science. It is interesting to see how our artistic idea of using plants as interfaces in 1992, has now developed into a whole area of research on intelligent hybrid interfaces  that make use of living plants to measure room temperature, controll ambient lights or to create sounds.
 Sommerer, C. and Mignonneau, L. 1993. “Interactive Plant Growing,” In: Visual Proceedings of the Siggraph ’93 Conference, ACM Siggraph, pp. 164-165.
 C. Sommerer and L. Mignonneau, “Interactive Plant Growing,” in Ars Electronica 93 – Genetic Art Artificial Life, K. Gerbel and P. Weibel (eds.), (Vienna: PVS Verleger, 1993) pp. 408-414.
 Tompkins, P. and Bird, C. 1989. The Secret Life of Plants. Perennial Library.
 Buxton, W. 1994. “Human skills in interface design.” In: L.W. MacDonald and J. Vince (Eds.). Interacting with virtual environments. New York: Wiley, pp. 1-12.
 Kuribayashi S., Sakamoto Y. and Tanaka H. 2007. ”I/O plant: a tool kit for designing augmented human-plant interactions, CHI’07 Conference on Human Factors in Computing Systems, San Jose, CA, USA, pp. 2537 – 2542.