Johan Christensen, chercheur à l’Université Carlos III de Madrid, Espagne, donnera un séminaire intitulé "Vibrant times for Phononic Metamaterials" le mercredi 1er mars 2017 à 11h00 en salle Pierre-Cotton de l’Institut Fresnel.
The boost experienced by acoustic and mechanical (phononic) metamaterial research during the past years has been driven by the ability to sculpture the flow of sound waves at will. Motivated by the desire to engineer artificial structures in the form of metamaterials and the quest to map quantum mechanical phenomena onto classical waves such as sound has led to vast possibilities in material designs for control of wave motion and the potential for engineering applications. Some striking material properties have shown in the past to be able to leave an objective acoustically concealed, hence they are cloaks of “unhearability”. Also, fascinating materials have been designed to be able to bend a ray of sound the “wrong” way when, for example, a loudspeaker turned on irradiates such artificial structure with a negative refraction index. In this talk, I like to review some of the key achievements made in this field and wish to address some of the unanswered questions that might lead to a breakthrough in the future.
Dr. Johan Christensen is a research fellow at the Instituto Gregorio Millán Barbany, Universidad Carlos III de Madrid. Broadly speaking, he is interested in wave physics and the theoretical description and numerical modeling of acoustic and mechanical metamaterials. The science of plasmonics in structured media also belongs to his line of research. In 2010 he was awarded his PhD at the Autonomous University of Madrid followed by a postdoctoral stay at the Spanish National Research Council until 2012 in Madrid as well. He was hired as an assistant research professor at the Techinical University of Denmark in Copenhagen until mid 2016. Dr. Johan Christensen is an international key player in acoustic and mechanical metamaterials and has given numerous plenary, keynote and invited lectures, chaired and organized conference sessions and was a member in technical and advisory boards of many international organizations and conferences. Given his remarkable track record he has obtained numerous awards and grants such as Marie-Curie Doctorate fellowship, Carlsberg fellowship, young elite researcher prize from the Danish Research Council, Ramon y Cajal fellowship and an starting grant from the European Research Council. These grants and prices amounted to a total of approximately 2.5m€ of funds raised.
Invitation : Sébastien Guenneau, équipe EPSILON