Selective and Collaborative Optimization Methods for Plasmonics: A Comparison

International audienceIn this paper, we optimize the size parameters of hollow nanospheres and nanoshells used in cancer photothermal therapy and we focus on two practical therapy cases: the visible range for shallow cancer and the near infrared for deep cancer. For this, we consider analytical models: the Mie theory for coated spheres. The investigated optimization methods are the Evolutionary Method (EM) and the Particle Swarm Optimization (PSO) which are based on competitiveness and collaborative algorithms, respectively. A comparative study is achieved by checking the efficiency of the optimization methods, to improve the nanoparticles efficiency

Electromagnetic Heat-induced in Meso-structures: Computation of Temperature in Metallic Dimers

International audienceThe illumination of a dimer metallic nanostructure is known to produce an in- tense source of light, with nanometric size. This con¯nement of light in the gap between the two material structures can induce an increase of the absorption of the electromagnetic energy in the nanaoantenna itself, and therefore its warm-up. The multiphysics problem associated to this photo-thermal e®ect is modeled through a Finite Element Method (FEM). This contribu- tion consists in computing both the electromagnetic ¯eld and the temperature, and discussing the in°uence of the gap, in the case of a bow-tie nanoantenna. The applications could be the development of nanodevices with thermal properties

Nanoshells for photothermal therapy: a Monte-Carlo based numerical study of their design tolerance

The optimization of the coated metallic nanoparticles and nanoshells is a current challenge for biological applications, especially for cancer photothermal therapy, considering both the continuous improvement of their fabrication and the increasing requirement of efficiency. The efficiency of the coupling between illumination with such nanostructures for burning purposes depends unevenly on their geometrical parameters (radius, thickness of the shell) and material parameters (permittivities which depend on the illumination wavelength). Through a Monte-Carlo method, we propose a numerical study of such nanodevice, to evaluate tolerances (or uncertainty) on these parameters, given a threshold of efficiency, to facilitate the design of nanoparticles. The results could help to focus on the relevant parameters of the engineering process for which the absorbed energy is the most dependant. The Monte-Carlo method confirms that the best burning efficiency are obtained for hollow nanospheres and exhibit the sensitivity of the absorbed electromagnetic energy as a function of each parameter. The proposed method is general and could be applied in design and development of new embedded coated nanomaterials used in biomedicine applications

Electromagnetic Heat-induced in Meso-structures: Computation of Temperature in Metallic Dimers

International audienceThe illumination of a dimer metallic nanostructure is known to produce an in- tense source of light, with nanometric size. This con¯nement of light in the gap between the two material structures can induce an increase of the absorption of the electromagnetic energy in the nanaoantenna itself, and therefore its warm-up. The multiphysics problem associated to this photo-thermal e®ect is modeled through a Finite Element Method (FEM). This contribu- tion consists in computing both the electromagnetic ¯eld and the temperature, and discussing the in°uence of the gap, in the case of a bow-tie nanoantenna. The applications could be the development of nanodevices with thermal properties

La parallélisation d'une méthode itérative pour la résolution d'un problème aux valeurs propres est intéressante, aussi bien sur un ordinateur à mémoire distribuée que sur un ordinateur à mémoire partagée

Thèse de doctorat annexe - UCL, 199

Etude théorique de l'interaction d'un système à deux électrons actifs avec des impulsions laser

Doctorat en sciences - UCL, 199

Numerical Study of Photoacoustic Pressure for Cancer Therapy

A commonly used therapy for cancer is based on the necrosis of cells induced by heating through the illumination of nanoparticles embedded in cells. Recently, the photoacoustic pressure shock induced by the illumination pulse was proved and this points to another means of cell destruction. The purpose of this study is to propose a model of the photoacoustic pressure in cells. The numerical resolution of the problem requires the accurate computation of the electromagnetism, the temperature and the pressure around the nanostructures embedded in a cell. Here, the problem of the interaction between an electromagnetic excitation and a gold nanoparticle embedded in a cell domain is solved. The variations of the thermal and photoacoustic pressures are studied in order to analyze the pressure shock wave inducing the collapse of the cell’s membrane in cancer therapy