Active motion of Janus particle doublets - experimental part (Simmchen Lab, Physical Chemistry)

Active matter is mostly explored using catalytic colloids, individually or in swarms (i.e. a collective).

While theoretical considerations predict interesting behaviours for different geometric assemblies of two individual Janus swimmers, experimental obstacles prevented the realization of these structures.

We have identified two alternative pathways for engineering such doublets, the optimization of the production, as well as the characterization of swimming behaviours will be the objective of this qualification work.

The key tasks of the project are listed below:

  1. Particle asymmetrization and characterization.
  2. Video microscopy and image analysis.
  3. Data evaluation and plotting.
  4. Comparison with theoretical predictions.

Key words: doublet formation, active motion, catalytic Janus particle


[1] Vuijk, H. D., Klemphan, S., Merlitz, H., Sommer, J. U., & Sharma, A. (2022). "Active Colloidal Molecules in Activity Gradients.", arXiv preprint arXiv:2205.07678.

[2] Simmchen, J., Katuri, J., Uspal, W. E., Popescu, M. N., Tasinkevych, M., & Sánchez, S. (2016). "Topographical pathways guide chemical microswimmers.", Nature communications, 7(1), 1-9.

[3] Yake, A. M., Panella, R. A., Snyder, C. E., & Velegol, D. (2006). "Fabrication of colloidal doublets by a salting Out− Quenching− Fusing technique.", Langmuir, 22(22), 9135-9141.


Dr. Juliane Simmchen
+49 (351) 463-37433 +49 (351) 463-37164
Prof. Dr. Jens-Uwe Sommer
+49 (351) 4658 750 +49 (351) 4658 752