Interesting cold fusion (?) device based on high voltage & frequency pulses introduced to membrane for reverse osmosis with COP > 120. Device is able to heat 500 grams of water from 22 ° C - 93 ° C during 720 seconds with using of battery input 1.7 Watts. Average life-time of membrane is 35 minutes. YT videos 1, 2. This device wetted my interest, as it show the way, how to do plasma electrolysis without actually doing a plasma. As you can imagine, during plasma electrolysis lotta energy gets wasted for formation of vapor film at the electrode and its ionization. This film is necessary for reaching sufficiently high electrostatic gradient, but its formation costs lotta energy. In addition, high frequency spikes are formed with less or more random interruption of arc discharge by cooling of film, which isn't apparently the way, in which the optimal frequency and voltage could be adjusted easily and preciselly.
The main secret of this device is apparently the semipermeable membrane used. The usage of deionized water of lowest conductivity as possible is reccomended, asi would enable to localize the electrostatic potential and avoid shortcuts. The voltage used is AC only without any DC component and from audioanalysis of video it seems, the frequency used is somewhere around 10 kHz. Such a voltage can be generated easily with AC source for ozonizers. Bellow is commonly accessible wholesale kit for reverse osmosis, IMO it could be directly used as an improvised reactor, once you solve the removal of excessive heat produced in it. Membrane must be kept wet after first usage, or it could be destroyed during drying.