Prof. Paweł Majewski from the UW’s Faculty of Chemistry and Przemysław Puła, a doctoral candidate at the UW’s Doctoral School of Exact and Natural Sciences, are among the authors of an article on laser drumming on ultrathin polymer membranes. The paper was published in the “Advanced Materials”.

The current uses of polymers include the construction of protective coatings, as auxiliary materials in biotechnology or in microelectronic devices.

Researchers from the University of Warsaw, in collaboration with a group of physicists from Adam Mickiewicz University in Poznań, have created ultra-thin polyamine and polyamine-silicon actuator membranes using a deposition technique called plasma-assisted polymerisation. Plasma is an ionised gas consisting of free electrons and positively charged ions. In plasma-assisted polymerisation, gaseous monomers – molecules of the same or several different compounds of relatively low molecular weight – are excited by the plasma. The result is highly cross-linked films that can be deposited on a variety of freely selectable substrates. This has a wide range of applications – from electronics to medical technology.

Unconventional membrane

“The technique we use facilitates the application of materials to a variety of surfaces, simplifying the conventional multi-step manufacturing process. The thin membrane material exhibits remarkable stability and exceptional mechanical properties. The 50-nm-thick polyamine membrane has achieved an impressive lateral size-to-thickness ratio of more than 40,000. If the thickness of the membrane corresponded to the thickness of a window pane, its size would be twice the length of a football pitch,” explains Przemysław Puła, one of the authors of the paper published in Advanced Materials.

Compared to most soft materials, whose response to changes in environmental factors such as humidity and temperature is limited by slow diffusion and molecular reorganisation, the movement of the membrane can be driven at speeds in excess of 1,000 cycles per second due to its extremely small thickness. This technology could find applications in wireless actuators, micromechanical vibration energy recovery and high sampling rate sensors.