Wouter Saeys

KU Leuven is advertising a PhD position in the MeBioS research unit, within the Biophotonics group, on laser scatter imaging for plant stress detection in greenhouse crops . The project sits at the intersection of optical sensing, image analysis, and precision agriculture, and is aimed at enabling earlier and more reliable detection of stress in greenhouse plants, especially tomato. The research responds to the need for smarter greenhouse control in protected cultivation, where optimizing the use of energy, water, nutrients, and labor is increasingly important. The project focuses on developing a new crop monitoring sensor that can support autonomous or semi-autonomous cultivation decisions based on actual crop data rather than visual inspection alone. Scientifically, the PhD will investigate how laser scatter images of plant leaves can reveal changes in scattering and absorption linked to plant microstructure, pigmentation, and water status. The work will combine camera vision with carefully designed illumination patterns and multiple wavelengths to detect subtle stress responses early, before they become visible to the human eye. The project aims to build a functional multispectral prototype of a scatter imaging sensor, analyze scatter images quantitatively, and validate the system on healthy and stressed plants under both laboratory and greenhouse conditions. The MeBioS unit has a strong track record in sensor technologies and data analysis for biological products and processes. Its Biophotonics group works with optical systems across the electromagnetic spectrum, including Vis/NIR spectroscopy, THz spectroscopy and imaging, hyperspectral imaging, thermography, and smart cameras. Data analysis expertise includes experimental design, chemometrics, process monitoring and control, artificial intelligence, and deep learning. The vacancy is targeted at highly motivated candidates with an MSc in Engineering (bioscience, electrical, or optical) or in Science (physics or photonics). Useful strengths include an affinity for greenhouse farming and plant stress detection, analytical ability in modelling light interaction with plant tissue, hands-on sensor prototyping, and programming experience in Matlab/Python and Labview. Strong communication, independence, initiative, and fluency in English are also emphasized. The position is offered as a full-time PhD contract for 1 year, with the possibility of extension up to 4 years after positive evaluation. Funding is in line with KU Leuven salary scales. Applications should be submitted through the KU Leuven online application tool by 30 July 2026 . The selection process is rolling, so early applications are encouraged. For more information, candidates may contact Prof. dr. ir. Wouter Saeys or Dr. Annelies Postelmans by email.

PhD opening at KU Leuven in the Division of Mechatronics, Biostatistics and Sensors (MeBioS), Department of Biosystems. This project develops innovative non-destructive optical sensing for the precision storage of pome fruit (apple and pear). The work sits at the interface of fruit physiology, spectroscopy, sensing technology, and data-driven modelling, with the goal of improving controlled atmosphere storage by accounting for biological differences between fruit batches. The research focuses on fruit microstructure, especially porosity, and its influence on gas exchange, respiration, ethylene production, and susceptibility to storage disorders such as internal browning. While micro-computed tomography can quantify porosity accurately, it is not practical for routine deployment. The project therefore investigates spatially resolved spectroscopy (SRS) as a promising alternative for measuring internal tissue structure non-destructively. The PhD will combine imaging and sensing with storage trials and model development. Fruit porosity will be measured using µCT, SRS calibration models will be developed, and fruit batches with contrasting porosity will be stored under controlled gas conditions. Respiration, ethylene production, and post-storage quality will be assessed to determine whether porosity can serve as a robust biomarker for storage optimisation. A further aim is to translate the approach toward portable, handheld SRS systems and validate them in semi-commercial storage environments. Expected outcomes include fundamental insights into postharvest physiology, predictive tools linking pre-storage measurements to storage performance, and guidelines for affordable sensing technology in practice. Applicants should have a Master’s degree in Bioscience Engineering, Physics, Mechanical/Electrical Engineering, Applied Biology, Agricultural Engineering, Biomedical Engineering, or a related field. Experience with spectroscopy, plant physiology, data analysis, or modelling is an asset. Strong analytical skills and enthusiasm for interdisciplinary research are important. The position offers a competitive salary, excellent supervision, access to advanced facilities, and opportunities for training, conferences, and collaboration within KU Leuven and an international research network. Deadline: 2026-08-15.