Stuttgart, Univ., Fakultät Physik, Diplomarb., 1996.

Zugl.: Münster (Westfalen), Univ., Diss., 2009. / Hergestellt on demand.

University, Diss., 2005--Düsseldorf.

Zugl.: Dortmund, Techn. Univ., Diss., 2009

De grands metteurs en scène, précurseurs d’un nouveau théâtre, tels que Maurice Maeterlinck ou Edward Gordon Craig, souhaitaient représenter la vie en ne se contentant plus de la présence corporelle de l’acteur mais en incorporant des éléments conventionnels à la scène. Ils refusaient la simple imitation du réel au profit d'un théâtre artificiel et symbolique, avec pour problématiques les questions de la représentation de la figure humaine et de l’illusion du vivant. Cette volonté de s’émanciper du corps de l’acteur tel qu’il est dans l’usage privé, dans le quotidien, par l’utilisation de masques, de marionnettes ou encore des techniques de leur temps, comme des jeux de lumières ou des effets d’optiques, annonçait déjà l’apparition des nouveaux médias sur le plateau. C’est dans cette filiation que sont apparus sur scène, dans les années 1990, de nombreux personnages inorganiques créées grâce à des projections vidéo sur supports bi ou tridimensionnels, des hologrammes, et par la présence de robots humanoïdes et androïdes. On retrouve cette volonté de remplacer les corps des acteurs par des personnages artificiels utilisant les technologies de notre temps avec les personnages vidéo de Denis Marleau et Stéphanie Jasmin, les hologrammes de Michel Lemieux et Victor Pilon ou encore les robots d’Oriza Hirata. Ces personnages atypiques, qu’ils possèdent ou non une matérialité sur scène, qu’ils soient physiques ou virtuels, possèdent différents niveaux de présences suivant leur intégration au plateau et la dramaturgie, leur autonomie et leurs interactions avec leur environnement ou les corps réels qui leur donnent la réplique et avec lesquels ils partagent la scène. Comme nous allons le découvrir, ces nouvelles pratiques et esthétiques théâtrales visant à utiliser des Personnages Artificiels Anthropomorphes et Technologiques (PAAT) questionnent l’impact de notre époque en pleine révolution numérique et robotique sur nos corporéités et notre humanité, ce qui soulève un certain nombre d'enjeux... / Famous directors, precursors of a new theater, such as Maurice Materlinck or Edward Gordon Craig, wanted to represent life on stage, weaving some conventionnal elements into the stage, instead of just making the best of the bodily presence of the actor on stage. They repressed the very simple imitation of real for some artificial and symbolic theatre questionning the representation of human's figure and the illusion of the living. Getting rid of the actor's body like it is in its private use, in its everyday life, through the use of masks, puppets or even elder technologies as light works or optical effects, heralded the appearence of the new medias on stage. Thereby, emerged back in the 90's, many inorganic characters made with video projections in two or three dimensions, holograms, and the presence of humanoids and androids. We can find that will to replace the actors' bodies with artificial caracters using technological projections in Denis Marleau and Stéphanie Jasmin's video caracters, Michel Lemieux and Victor Pilon's holograms, and again in Oriza Hirata's robots. All these atypical characters, whether they own or not some materiality (or corporality) on stage, or that they are physical or virtual, all of these own different levels of presence according to their integration on stage and dramaturgy, to their self-suffiency and to the interplays they share with each their environnement and the real bodies with which they interact and perform. As we will see, these new theatrical and aesthetics practices that aim to use some Anthropomorphic and Technological Artificial Characters, do question the impact of our time, dealing with digital and robotic revolution, on our corporealities and our humanity, definitively raises a number of issues…

In Optogenetics, cells, e.g. neurons or cardiac cells, are genetically altered to produce for example the lightsensitive protein Channelrhodopsin-2. Illuminating these cells induces action potentials or contractions and therefore allows to control electrical activity. Thus, light-induced cell stimulation can be used to gain insight to various biological processes. Many optogenetics studies, however, use only full field illumination and thus gain no local information about their specimen. But using modern spatial light modulators (SLM) in conjunction with computer-generated holograms (CGH), cells may be stimulated locally, thus enabling the research of the foundations of cell networks and cell communications. In our contribution, we present a digital holographic system for the patterned, spatially resolved stimulation of cell networks. We employ a fast ferroelectric liquid crystal on silicon SLM to display CGH at up to 1.7 kHz. With an effective working distance of 33 mm, we achieve a focus of 10 µm at a positioning accuracy of the individual foci of about 8 µm. We utilized our setup for the optogenetic stimulation of clusters of cardiac cells derived from induced pluripotent stem cells and were able to observe contractions correlated to both temporal frequency and spatial power distribution of the light incident on the cell clusters.

Techn. Universiẗat, Diss., 2003--Darmstadt.

The generation and application of human stem-cell-derived functional neural circuits promises novel insights into neurodegenerative diseases. These networks are often studied using stem-cell derived random neural networks in vitro, with electrical stimulation and recording using multielectrode arrays. However, the impulse response function of networks is best obtained with spatiotemporally well-defined stimuli, which electrical stimulation does not provide. Optogenetics allows for the functional control of genetically altered cells with light stimuli at high spatiotemporal resolution. Current optogenetic investigations of neural networks are often conducted using full field illumination, potentially masking important functional information. This can be avoided using holographically shaped illumination. In this article, we present a digital holographic illumination setup with a spatial resolution of about 8 µm, which suffices for the stimulation of single neurons, and offers a temporal resolution of less than 0.6 ms. With this setup, we present preliminary single-cell stimulation recording of stem-cell derived induced human neurons in a random neural network. This will offer the opportunity for further studies on connectivity in such networks.