Microfluidic devices for biological sample collection and processing
Time: Mon 2026-06-15 10.00
Location: D3 Lindstedtsvägen 5, Campus
Video link: https://kth-se.zoom.us/j/67299148551
Language: English
Subject area: Electrical Engineering
Doctoral student: Ellinor Hedberg , Mikro- och nanosystem
Opponent: Professor Ashleigh Theberge, Department of Chemistry, University of Washington, Seattle, WA, USA
Supervisor: Professor Niclas Roxhed, Mikro- och nanosystem; Professor Göran Stemme, Mikro- och nanosystem; Assistant Professor Daniel Hagey, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
QC 20260519
Abstract
Sample collection and processing are fundamental components in the study of a multitude of biological systems. The reliability of downstream analyses depend greatly on the integrity of the collected material and the processing steps. Consequently, efforts have been directed to the refinement of sampling strategies to collect samples while still maintaining quality, reducing invasiveness to allow for longitudinal and frequent monitoring, and enable decentralized sampling, simplifying the overall workflow. Thus, these are approaches that reduce the logistical burden and enable more decentralized, or field-based collection approaches that can broaden the context of where biological data can be obtained.
This thesis presents novel microfluidic devices, designed to simplify sample collection and processing, for both plant and human systems, with the aim to detect environmental stressors and biomarkers of disease. Through the reduction of procedural complexity this work aim to support more accessible and easier sampling approaches that could be applied in different biological and health care settings.
This is done through the development of a plant sap sampling device that is designed to enable low invasive sampling in-field. The device presents a disposable system with integrated drying, inspired by the dried blood spot concept for human diagnostics to enable collection and storage of a sap sample without the need of a cold chain. This device is also further developed and combined with a biosensor for detection of abscisic acid, a phytohormone used for stress signaling in plants, thus presenting on-site detection capabilities of drought and environmental stress. Additionally, the device is used for longitudinal monitoring of plants in an ozone environment where machine learning was used to identify predictors of ozone exposure in the phytohormonal fingerprint.
The work also includes a device for a different biosample, blood. Here an autonomous capillary microfluidic filtration device for whole blood sample processing to extract nanoparticles and extracellular vesicles is presented. The device is based on a dual filtration approach to directly process a whole blood sample into a nanofiltrate. The device is characterized with polystyrene beads, synthetic extracellular vesicles and liposomes to verify functionality and is further used to evaluate cancer patient samples to detect biomarkers of disease.
Together, these contributions present technological progress in the field of on-site sampling for plant sciences and a novel means of blood filtration for the analysis and detection of disease biomarkers. Thus, these contributions provide low invasive, patient and plant centric sampling approaches for potential applications in environmental monitoring, nutrient analysis, disease and treatment tracking or for screening purposes.