Katsonis joined the Centre National de la Recherche Scientifique (CNRS) in 2007 and started to work on light-responsive chiral liquid crystals. She was made a Group Leader at the University of Groningen and held a visiting position at KU Leuven. In 2012 she was awarded a Royal Society International Exchange grant to work with Steve Fletcher on light responsive polymers. Katsonis proposed the materials could be used for microfluidics or soft robotics. Her research is inspired by nature, where helical structures are often created for movement.
She moved to the University of Twente in 2013, and was promoted to Professor in 2016. She returned to the University of Groningen as Professor of Active Molecular Systems in 2020. Katsonis has worked on squishy light responsive materials, which can convert light energy into mechanical work. She demonstrated that it is possible to switch between left and right-handed helixes in cholesteric liquid crystals using light. She has also showed that it is possible to use twisted liquid crystals as organising templates to design self-assemblies of superparamagnetic nanoparticles. In 2017 she was awarded a European Research Council Consolidator Grant in nanotechnology. Her recent work has been concerned with unravelling the molecular origin of purposeful motion, both in space and time at the nanoscale.