Vacancies
There are currently 3 possibile vacancies for PhD students (2009 - 2012). A short description is given below. Please contact prof. Christ Glorieux for more information.
1 Laser ultrasonic and photothermal research of heterogeneous structures
Laser excited acoustic and thermal waves have the interesting property that they can deliver information about material properties on locations which are inaccessible for other techniques. In this research we study reflection, transmission, diffraction and nonlinear effects of thermal and elastic waves from the sub-Hz till GHz range using heterodyne diffraction, stroboscopic interferometric imaging, IR thermography and advanced data processing techniques (Gabor transformation, neural network recognition). In this way, in a non-contact way, it is possible, besides the elastic characterization of materials, to determine their continuous or multilayered depth structure, and to detect and identify sub-surface defects, from mm to micrometer and nanometer scale.
2 Photothermal, dielectric and laser ultrasonic investigation of frequency dependent thermophysical properties of soft matter
The transition from a liquid to a solid state of matter sometimes goes along with a colorful and complex pallet of physical properties, which leads to interesting technological applications. Molecules in liquid crystalline compounds (LCD-displays) are aligning or show a liquid-like layered structure. Supercooled liquids (polymers, heat storage materials, speed-dependent mechanical coupling fluids, ionic liquids) behave solid-like or liquid-like depending on the time scale of observation. Some materials (memory alloys) have a shape memory when cooling. In some gels the elastic wave velocity is extremely small, leading to spectacular effects. Using thermal, elastic and dielectric spectroscopy we study these strongly frequency and temperature dependent thermo-elastic phenomena in the sub-Hz – GHz range. For this we use IR thermography, photopyroelectric spectroscopy, dielectric spectroscopy and laser heterodyne diffraction and optical interferometry.
3 Spectroscopic response of biological material on ultrasonic excitation
An interdisciplinary consortium around the research group: Materials Performance and Non-Destructive Evaluation is seeking a scientist or engineer (master or equivalent) for its research on the development of an integral technology for the spectroscopic in-situ analysis of the molecular response of biologic material on ultrasonic excitation.
BACKGROUND ON THE PROJECT Ultrasonic waves can interact with biological material in different ways. In the case of ultrasonic diagnosis and molecular acoustics, the interaction is inert and nondestructive, and in the case of ultrasonic therapy, ultrasonic waves are used to stimulate physiological effects. A literature review reveals that many research groups using ultrasound for biological or biomedical purposes normally use acoustic standard instrumentation where not all acoustic parameters can be controlled or measured. On the other hand, research on ultrasonics in material science and physics is very advanced, but the transfer of their knowledge into biophysical applications is still limited. This project aiming in the in-situ investigation of the molecular behaviour of biomembranes and protein assemblies under ultrasonic excitation wants to respond to this situation by establishing of a multidisciplinary co-operation between different academic disciplines, such as engineering science, physics and biochemistry.
