Traditional microfluidic devices make use of physical channels and mechanical actuators, in which geometries and functionalities are intimately related to one another, i.e., changing the flow field requires change at the mechanical level. Recently, we introduced a concept in which a microfluidic chamber with no preset structures or active mechanical components can be dynamically configured to produce desired flow fields . We demonstrated experimentally the establishment of a bidirectional field by controlling the surface charge using either surface chemistry or embedded electrodes .
We are currently studying the use of the bidirectional flow field as a mechanism to separate molecules and particles based on their diffusivities, investigating the effect of the liquid properties (pH and ionic concentration) on the separation performance. Further, we will explore alternative strategies to obtain bidirectional flows, with focus on decoupling the flow actuation from the liquid properties.
This project will be performed at IBM Research – Zurich, where the student will be exposed to an active, vibrant and stimulating research environment.
The main task will be to explore, characterize and develop different strategies to obtain bidirectional flow fields and study its application for separation of biochemical species and particles. The student will:
- Characterize the surface charge properties of several substrates for different buffer conditions.
- Study and characterize the diffusion-convection transport of particles and molecules in a bidirectional flow field.
- Identify and test several methods to create surface charge patterns of hydrophobic and oleophobic regions.
- Design and test microfluidic configurations to optimize the separation efficiency.
- Explore alternative approaches to control the surface charge of a substrate, e.g. light-driven actuation.
The student must have a strong interest in Transport Phenomena and/or Surface Chemistry. He/She must have a background in at least one of the following disciplines: micro/nanotechnology, applied physics, chemical or mechanical engineering, physical-chemistry, electrical engineering, biomedical engineering.
Above all, the student must be motivated, self-driven and keen to work in a biomedical microtechnology environment
Time frame and contact
Starting date is flexible, and the project duration is six to nine months. To apply, please send to Dr. Govind Kaigala (firstname.lastname@example.org) a single PDF file including (1) cover letter, (2) resume and (3) transcript of records of bachelor and master studies.
 Paratore F. et al., PNAS, May 21, 2019 116 (21) 10258-10263
 Bacheva V., Paratore F. et al., Angewandte Chemie, under revision.