The purpose of the course is to provide the theoretical basis for understanding the theory and the principles of photoacoustic and photothermal techniques and related instruments, and to discuss the main applications for nonsdestructive evaluation and testing of materials in many different fields: industry, environment, energy, but also biology, medicine, nanoscience, and in the emerging sector of agri-food. Final comparisons will be introduced among the diagnostic techniques. The course contains also some practical activities for the data analysis and processing.
Students are expected to acquire understanding of the basic physical principles of photoacoustic and photothermal techniques (PA&PT) for material testing, including the latest trends in the field.
photoacoustic, photothermal, non-destructive testing
|✔ 専門力||教養力||コミュニケーション力||✔ 展開力(探究力又は設定力)||✔ 展開力(実践力又は解決力)|
The course will be subdivided in 6 lectures of 1h 30m each + 1 open course for students and senior scientists
|第1回||In this first lecture the general purpose of the course will be introduced, together with some historical background starting from the experiments with the “Photophone” made by A.G. Bell in 1880. The basic principles of photoacoustics technique will be also provided, with a simple explanation of the photoacoustic effect by means of the “thermal piston model” by A.Rosencweig and A.Gersho in 1976. The lecture will be concluded by showing the time-line of the significant events in photoacoustic science and the development of innovative detection systems. The applications will be introduced and discussed later from Lectures 4.||None|
|第2回||In this second lecture the basic principles of most of the known photothermal techniques will be provided: in particular photothermal deflection, photothermal displacement, modulated optical reflectance, photo-pyroelectric, laser picosecond acoustics and photothermal radiometry will be introduced, discussing the main experimental setup, and showing how the detected signal is related to the heat source or to the induced temperature increase. The applications will be introduced and discussed later from Lectures 4.||None|
|第3回||the third lecture will be devoted to the thermal wave physics. The mathematics of the thermal waves will be introduced starting from both Fourier and Energy conservation laws. The thermal diffusion length, the thermal effusivity will be defined starting from thermal conductivity, diffusivity and heat capacity. Several phenomena as the generation, propagation, reflection, refraction, interference and back scattering, of thermal waves will be deeply discussed, showing how they can be detected and used for NDE & NDT and for the determination of thermophysical properties of materials.|
|第4回||In this fourth lecture the main applications of photoacoustic and photothermal techniques will be introduced: in particular we show how to measure the thermal diffusivity, optical absorption of homogeneous material as for example solid sample (metals, semiconductors, photovoltaics, superconductors), liquids or gases and pollutants. Specific applications will be mentioned in biology and agri-food science.|
|第5回||In this fifth lecture it will be shown how photoacoustic and photothermal techniques can be successfully applied to nanomaterials, nanophotonic and nanophononic band gap materials, nanostructured materials, opals etc.|
|第6回||The sixth lecture is devoted to mention the nanoscale heat processes which doesn’t follow the Fourier law, exploring which are the photoacoustic and photothermal techniques applicable and in which regimes. Future perspectives to new possible applications will be also eventually given. In addition some exercises and numerical simulations will be proposed to students directly in the class.|
|第7回||“open course”. The proposed title for the last lecture will be: “Recent advances and future perspectives in photoacoustic and photothermal science”||None|
will be informed in the lecture.
will be informed in the lecture.