Department of Applied Physics

Active Matter

The research group focuses on active matter, non-equilibrium systems and fluids and colloids in EM fields.

Current focus

  • Active matter: We investigate behavior of biological micro/milliswimmers in complex environments and interfaces. We also develop, engineer and synthesize artificial systems that mimic naturally occurring active materials.
  • Non-equilibrium systems: Active matter is just one example of non-equilibrium systems. We are interested in the transition between equilibrium and non-equilibrium self-assembly.
  • Fluids and colloids in EM fields: We are interested in the ways that fluids and colloidal matter interact with electric and magnetic fields. We also develop new electromagnetic microtweezing tools for soft matter research.

Open positions

We always welcome applications from enthusiastic researchers of all levels (from students to post-docs). Contact Prof. Jaakko Timonen for details.

Research highlights

  • Daniel D., Timonen J.V.I., Li R., Velling S.J., Aizenberg J.A.,
    Oleoplaning droplets on lubricated surfaces,
    Nature Physics (2017). (link)

  • Timonen J.V.I., Raimondo C., Pilans D., Pillai P.P., Grzybowski B.A.,
    Trapping, Manipulation, and Crystallization of Live Cells Using Magnetofluidic Tweezers,
    Nanoscale Horizons 2, 50-54 (2017). (link)

  • Timonen J.V.I., Demirörs A.F., and Grzybowski B.A., 
    Magnetofluidic Tweezing of Nonmagnetic colloids,
    Advanced Materials 28, 3453-3459 (2016). (link)

  • Timonen J.V.I., Latikka M., Leibler L., Ras R.H.A., and Ikkala O., 
    Switchable Static and Dynamic Self-Assembly of Magnetic Droplets on Superhydrophobic Surfaces,
    Science 341, 253-257 (2013). (link) (press release)

  • Timonen J.V.I., Latikka M., Ikkala O., Ras R.H.A., 
    Free-Decay and Resonant Methods for Investigating the Fundamental Limit of Superhydrophobicity,
    Nature Communications 4, 2398 (2013). (link) (press release)

  • Timonen J.V.I., Seppälä E.T., Ikkala O., and Ras R.H.A., 
    From hot-injection synthesis to heating-up synthesis of cobalt nanoparticles: observation of kinetically controllable nucleation,
    Angewandte Chemie International Edition 50, 2080-2084 (2011). (link)


  • Wet chemistry lab equipped for nanoparticle/colloid synthesis
  • Bioroom equipped for BSL1 micro-organisms
  • Physical measurements lab equipped with
    -  Nikon Ti-E and Zeiss Z1 inverted microscopes
    -  Andor iXon Ultra 888 EMCCD and Zyla 4.2 sCMOS cameras
    -  Photron APX-RS high-speed camera (color, 1024x1024 @ 3000 fps)
    -  Keysight/Keithley precision measurement units and power supplies
  • Other facilities at our disposal
    Nanomicroscopy center (electron microscopy, x-ray scattering) 
    Micronova (nano/microfabrication)
    -  Department of Applied Physics (general tools and equipment)

Latest publications

Adipokine Leptin Co-operates With Mechanosensitive Ca2 +-Channels and Triggers Actomyosin-Mediated Motility of Breast Epithelial Cells

Anna Acheva, Tytti Kärki, Niccole Schaible, Ramaswamy Krishnan, Sari Tojkander 2021 Frontiers in Cell and Developmental Biology

Ferrofluidic Manipulator

Zoran Cenev, P. A. Diluka Harischandra, Seppo Nurmi, Mika Latikka, Ville Hyninen, Robin H.A. Ras, Jaakko V.I. Timonen, Quan Zhou 2021 IEEE/ASME Transactions on Mechatronics

Trpv protein family—from mechanosensing to cancer invasion

Tytti Kärki, Sari Tojkander 2021 BIOMOLECULES

Diversity of non-equilibrium patterns and emergence of activity in confined electrohydrodynamically driven liquids

Geet Raju, Nikos Kyriakopoulos, Jaakko V.I. Timonen 2021 Science Advances

Chlamydomonas reinhardtii swimming in the Plateau borders of 2D foams

Oskar Tainio, Fereshteh Sohrabi, Nikodem Janarek, Juha Koivisto, Antti Puisto, Leevi Viitanen, Jaakko Timonen, Mikko Alava 2021 Soft Matter


Oskar Tainio, Fereshteh Sohrabi, Nikodem Janarek, Juha Koivisto, Antti Puisto, Leevi Viitanen, Jaakko V.I. Timonen, Mikko Alava 2021

Water droplet friction and rolling dynamics on superhydrophobic surfaces

Matilda Backholm, Daniel Molpeceres, Maja Vuckovac, Heikki Nurmi, Matti Hokkanen, Ville Jokinen, Jaakko Timonen, Robin Ras 2020 Communications Materials

TRPV6 calcium channel directs homeostasis of the mammary epithelial sheets and controls epithelial mesenchymal transition

Tytti Kärki, Eeva Kaisa Rajakylä, Anna Acheva, Sari Tojkander 2020 Scientific Reports

Ferrofluid Microdroplet Splitting for Population-Based Microfluidics and Interfacial Tensiometry

Mika Latikka, Matilda Backholm, Avijit Baidya, Alberto Ballesio, Amandine Serve, Grégory Beaune, Jaakko V.I. Timonen, Thalappil Pradeep, Robin H.A. Ras 2020 Advanced Science
More information on our research in the Research database.
Research database

Earlier publications (2010 - 2017)

Scientific publications by the Active Matter group pre-2018.

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