Interactive device, 2013
Dominique Peysson and Hsinli Wang
Following the series of works "Les Limbo" by Hsinli Wang

Sept 2013 - Aug 2014
Water, glass, radiator, fan, computer, sensors, LED bar
Two 80X60X40cm parallelepipeds, ESPGG showcases,
10 rue Vauquelin, 75005 Paris
Scientific Advisor Daniel Beysens, PMMH laboratory, ESPCI.
Engineering assistant Cyrille Henry, lights assistant Annie Leridan
As part of the Reflective Interaction/EnsadLab program
(Research laboratory of the National School of Decorative Arts).
With the support of PSL


Hydrophily is a work on the thread between the ephemeral and the permanent. The fragile fog patterns can change very finely depending on the outside temperature. The size of the drops that constitute the very material of the drawing increases very slowly over time, day after day. The light from the systems installed in the shop windows responds interactively to the presence of the spectators...


The title of the work refers both to the hydrophilic plants which let their pollen carry with the flow of water and to the specific physico-chemical properties of the material which controls the presence or not of mist on the surface. It is the current of a river or the flow of a pond that will allow hydrophilic plants, such as Potamogeton, to pollinate and therefore reproduce.

Planche de Potamogetons, plantes d’eau hydrophiles

The circuit of water which evaporates, condenses on the wall, then remains in the form of drops which gain in thickness and flows in places to join the stagnant water, recalls the flow necessary for reproduction. of these plants. A slow and hesitant dynamic: that of the initially very fine and particularly sharp and luminous fog image, which then loses its resolution as each of the drops, like pixels, increases in size. Gently melancholy, like the surroundings of ponds, the fog boxes play with the light and give us to see ghostly images straight out of imaginary worlds.

A work of art and science


Hydrophily also refers to the specific character of certain surfaces that “like” water: a hydrophilic surface will favor its contact with water rather than with air or any other fluid. The realization of this installation could be optimized thanks to the physicist Daniel Beysens and the chemist Niki Baccile.

When humid air is in contact with a colder temperature surface, the water condenses on the wall, forming the fog that we know well. The appearance of this mist is highly dependent on the angle formed by the drops of water on the support.


For a very hydrophilic surface, the angle is close to zero and the water forms a transparent film. Conversely, drops placed on a very hydrophobic surface are almost spherical. This is the lotus effect.

These surface properties are controlled by the molecular structure of the surface, as well as by its physical structuring. The aesthetics of the mist obtained, from transparent to iridescent white, can therefore be controlled by means of surface treatments that modify its properties.


Much research is currently being carried out in laboratories to refine the possible responses according to the different specifications. Hydrophily has taken advantage of this research to generate a very white mist that can last satisfactorily for several months in the closed enclosure of the pools.

De gauche à droite, de haut en bas]Test de filtre ● Programmation lumière ● Test lumière ● Cherche des paramètre de lumière ● Installation des capteurs infra-rouge ● Réglage fin des tonalités de lumières

An installation that plays with light

De gauche à droite, de haut en bas]Test de filtre ● Programmation lumière ● Test lumière ● Cherche des paramètre de lumière ● Installation des capteurs infra-rouge ● Réglage fin des tonalités de lumières
From left to right, from top to bottom]Filter test ● Light programming ● Light test ● Search for light parameters ● Installation of infrared sensors ● Fine adjustment of light tones

To highlight the delicacy of the steam patterns, the lighting installed on the system allows light to circulate along the basin. The movement of the light highlights the thickness of the drops when they get bigger, like so many small magnifying glasses reflecting the light source on their side, from right to left irregularly. Interactive, the light responds to the presence of passers-by in the street, who can become spectators in front of the windows. The movements of light are then made according to a specific dynamic, faster and evolving according to the public, varying at the same time in intensity, in tonality and in position. The colors change from cold bluish white to warm white, more yellow, gradually. The control of the lights was carried out with the help of Cyrille Henry and Annie Leuridan, supervisors specializing respectively in programming and lighting from EnsadLab, with the critical eye of Omar Benyebka from the ESPGG.

Watch the time go by

Hydrophily is an installation that evolves over time, according to two distinct dynamics.

The short times correspond to the moment when the mist appears for the first time, in a delicate, almost magical way, little by little.

Once formed, the mist remains, but changes with the passing days. The quantity of water condensed in the drops increases: the mass of water in each then varies linearly as a function of time, and their radius as the cubic root of time. The small drops will tend to move to join the larger drops. There will then be coalescence. Then the drops grow until they touch and merge. Droplet growth accelerates and then varies linearly with time on a flat surface. Finally, some drops grow so big that they end up flowing along the substrate, if it is not horizontal. After that, the system stabilizes and the drawing of drops no longer evolves.

Crossed by the light, the larger drops will give less contrast, but will take thickness. The light will be trapped there, and the patterns will change in appearance depending on the orientation of the light. The large drops will thus make it possible to give "body" to the drawn surface, introducing the possibility of a dynamic in response to that of light. This is no longer a drawing, but a sculpture of drops.

Finally, the size of the drops defines the "resolution" of the image that can be obtained with the fog, as do the pixels of a digital image. The larger the drops, the lower the resolution. The drawing is getting easier, little by little. A bit like a memory image that loses its details with the passage of time, while increasing its consistency and emotional strength.

The viewer can then stand there, in front of the windows, and watch time go by.