Optical vibrational spectroscopy is a very powerful analytical technique. By scattering or direct absorption light can address molecular vibrations, that result in a unique fingerprint for (bio)molecules. There is increasing interest for such techniques for biomedical applications as they allow non-invasive determination of local molecular content, which can be a measure of the tissue disease state. Broad deployment of these techniques is still hindered by the limited penetration depth of light in tissue, due to scattering and/or absorption. This issue can be partially relieved by so-called photo-acoustic detection, where light absorption is not measured through analysis of the reflected or scattered light, but by measurement of acoustic waves, generated in the tissue upon light absorption. Acoustic waves in the right frequency range can travel through tissue without notable scattering, allowing detection of light absorption of deep subsurface regions, which would be impossible using analysis the reflected light. This technique has been successfully demonstrated in a number of biomedical applications, for both imaging, spectroscopy and combinations of both. These demonstrations still typically require large instrumentation and/or suffer from low sensitivity of the used acoustic detectors.
Imec is working on different schemes for highly sensitive acoustic transducers, not necessarily requiring direct contact with the skin/tissue, which would greatly increase the possible use cases of the technique. In this PhD project, you will focus on demonstrating actual photo-acoustic spectroscopy on relevant tissue phantoms and actual tissue by means of stimulated Raman scattering, which allows much deeper penetration than infrared spectroscopy, despite the weak signal.
Imec is soliciting enthusiastic PhD candidates to build and validate this technique using off-the-shelf and novel imec components. The goal of the PhD is to determine the ultimate limits of the technique, in terms of penetration depth and sensitivity.
Required background: Engineering Technology, Engineering Science, Physics, Analytical Chemistry or equivalent
Type of work: 15% literature, 55% experimental, 30% modeling
Supervisor: Pol Van Dorpe
Daily advisor: Veronique Rochus, Hilde Jans
The reference code for this position is 2020-089. Mention this reference code on your application form.
Chinese nationals who wish to apply for the CSC scholarship, should use the following code when applying for this topic: CSC2020-48.