[henrikf]

On the same PSLV C38 rocket was Aalto-1, a 3U cubesat that has electrostatic plasmabrake that is a different de-orbiting experiment. It uses 100 m long hair thin wire that is electrically charged and brakes the satellite by interaction with the ionosphere. https://www.electric-sailing.fi/papers/Plasmabrake.pdf

It has an advantage of not needing any propellant and being very light weight but it doesn't work above the ionosphere. It should work for de-orbiting small satellites in LEO. The same principle should be possible to be used as a solar sail for interplanetary travel by interacting with the solar wind.