PhD on Agrifood sensing using electronically generated THz radiation

Terahertz (THz) radiation fills in the gap between high-frequency microwaves and low-frequency infrared radiation. In the 1990s, optical generation and detection of this radiation was a true gamechanger by opening up this last undiscovered part of the electromagnetic spectrum. Applications in fields such as the agriculture, food, industrial, medical sectors were then possible to explore. Recent work on agriculture produces have shown that THz spectroscopy allows to determine non-destructively and without contact the moisture content of leaves to evaluate plant well-being. For food produces, first evidence is reported about the identification of key components such as edible oils, moisture and sugars. For many applications, however, a real impact of the technology is hampered by the surrounding liquid, a lacking signal to noise ratio of THz equipment, the absence of adequate signal processing schemes, and importantly the large form factor and costs. The ultimate challenge for designing a THz-based sensor in these sectors is thus to uniquely identify targeted species of industrial or societal interest in a complex biomolecular system with a small and affordable THz spectroscopic system. For the latter aspects, electronic THz generation and detection, having a form factor of the order of the size of ICs, lower costs and larger power than commercial optical THz technologies, is expected to provide a prosperous path.

Research

The project has the goal to study the opportunities of THz spectroscopy and imaging in the field of agriculture and food and accordingly to the requirements design and fabricate an IC-based broadband THz generation module. The research of the candidate will focus on the study of a particular societally relevant problem in either the agriculture and/or food domain, where THz technology can make a true difference as compared to the state-of-the art. Hereto, the candidate will first allocate the appropriate THz frequency range and design and fabricate an IC-based THz emitter that extends the upper frequency limit of IC based spectroscopy modules to 1 THz or beyond. On the application side, the candidate will need to design a dedicated measurement setup, perform experiments autonomously and in collaboration with e.g. agriculture universities, food institutes, and develop signal processing algorithms. The latter ones may include analysis based on chemical and physical interactions, complemented with contemporary AI principles. Collaborations with the Wageningen University & Research are foreseen.