The separation and enrichment of bio-particles is a most common need in bioanalytical applications. Examples include the purification of nucleic acids for next-gen sequencing or for detecting infectious diseases, complex extraction steps for protein purification or the isolation of exosomes for diagnosing cancer. Bio-particles include nucleic acids, proteins, extracellular vesicles, viruses and bacteria. Current technologies such as filtering, centrifugation, or liquid chromatography can separate or enrich bio-particles, but are difficult to integrate in small devices. The difficulty of bio-particle separation is a major bottleneck that prevents many microfluidic techniques from being widely used in commercial applications. The focus of this PhD is to develop an electro-capturing method and device that can separate and enrich biomolecules in a microfluidic format.
The electrical properties of bio-particles, such as charge or dielectric constant, allow them to be effectively manipulated by the electrostatic force in an electric field. Electrical bio-particle manipulation provides many advantages over competing techniques such as high bio-specificity, simple structure, low cost fabrication, programmable operations, etc. This technique, often cited as “dielectrophoresis”, has been demonstrated for isolating large bioparticles, such as capture of tumor cells from blood. The same physical principles are also promising for smaller bio-particles, however, with new challenges. As the electrostatic force scales down with bio-particle size, it starts to compete with other effects that cannot be ignored, such as electrothermal flow and Brownian motion. A most promising solution to address the challenge is downsizing the electrode dimensions and spacing to greatly improve the electric field and gradient, hence strengthening the electrostatic force over other physical effects.
In this PhD, the electrical properties of bio-particles and the consequential determination of the electrode geometry, material and operation parameters will be studied in this PhD topic. We will devise technical methodologies for extraction of bio-particles, and the feasibility toward semiconductor-microfluidics integration. Importantly, we will assess which, if any, synergies between the various methodologies may be leveraged for practical killer applications. The thesis work will be including hybrid electrical and microfluidic design and fabrication in imec’s cleanroom. The device will be characterized and used for bio-particle capture measurements. This topic will be supervised and supported by a team of physicists, biochemists and engineers in the imec life sciences department.
Required background: physics, electrical engineering
Type of work: specify percentage dedicated to literature, technology study, experimental work, other
Supervisor: Liesbet Lagae
Daily advisors: Chengxun Liu, Maarten Fauvart
The reference code for this PhD position is SE1712-24. Mention this reference code on your application form.