Bachelor or Master assignments

Stiffness Effect of PDMS Scaffold for Neuronal Cell Culturing


Cells are sensitive to the mechanical properties of their environment. In tissue, the extracellular matrix (ECM) influences the function of cells, providing not only a physical scaffold, but also chemical cues for cell’s growth and behavior.[1] Networks of neurons cultured on-chip can provide insights into both normal and disease-state brain function. Our goal is to combine microfluidics with tissue engineering to create a ‘living brain’, generating realistic in vitro* neural circuitry, which can be used to standardize experimental neuronal cell culture. The ability to guide neuronal growth in scaffolds with specific, artificially-designed patterns allows us to study how brain function follows form.

Properties such as the stiffness and topography of the scaffold material have a significant effect on the number of primary neurons and astrocytes attached, as well as on the direction of their outgrowths.[2,3] Usually, materials suitable for nanopatterning have a stiffness far above that of the extracellular matrix (ECM). Study on optimizing the stiffness of the nanopattering material, e.g. polydimethylsiloxane (PDMS)[4], is a necessary link for approaching a realistic on-chip neuronal cell culturing model.


The student will perform experiments on PDMS soft lithography, manipulate the stiffness of nanopatterned PDMS thin films, and characterize the structural and mechanical information of these films. The optimized parameters and process will be utilized in further study on neuronal cell culturing.

Ready-to-learn technical skills include soft lithography, material mechanical analysis, scanning electron microscopy, atomic force microscopy, etc.

The interested candidate is expected to have ideally a background knowledge of material science.

*in vitro: studies that are performed with cells or biological molecules studied outside their normal biological context.


  1. K. Franze, P. A. Janmey, and J. Guck. Annu. Rev. Biomed. Eng., 15, 227-251 (2013).
  2. P. C. Georges, W. J. Miller, D. F. Meaney, E. S. Sawyer, and P. A. Janmey. Biophys. J. 90, 3012-3018 (2006).
  3. F. Johansson, P. Carlberg, N. Danielsen, L. Montelius, and M. Kanje. Biomaterials. 27, 1251 (2006).
  4. D. Qin, Y. Xia, and G. M. Whitesides. Nat. Protoc. 5, 491-502 (2010).

Contact information

Sijia Xie, PhD student in Mesoscale Chemical Systems group

Email: s.xie