The prototype in the linked video was first tested back in 2023, and since then a few startups have set their sights on the technology (e.g. Nomadic Drones and Voltair).
When working on the linked prototype we ran into some fundamental issues. Firstly, the recharging will only work with AC lines, and there's currently a lot of hype around UHVDC lines which are not compatible. Secondly, the AC lines must carry substantial current (ideally thousands of amps) for the recharging to not take forever. You can of course carry a much larger transformer on the drone to compensate, but this will in turn severely limit your flight time (ours was 1kg on a drone of 4.5kg and we could charge with 50W from 300A line current). You also have to account for significant daily fluctuations in the line current. It'll be interesting to see how the tech evolves, and I'll definitely be following these startups closely.
In their report (https://gitlab.com/hybrid-drone/paper) the authors mention that they implemented one controller for flying and another for diving. The transition seems to be initiated manually, but they propose a few ways of automatic detection and transition.
As far as I can tell from their report (https://gitlab.com/hybrid-drone/paper), the authors did not consider underwater RF transmissions in their prototype design and simply use standard COTS components typically used for DIY UAVs.
A more relevant metric than admins/professor would be admin staff/scientific staff. Given that a research group under a professor will probably contain numerous associate professors, assistant professors, postdocs, PhDs, and research assistants who all generate some admin workload, 3 admins per professor does not sound outlandish.
I'm not sure what the person meant in the comment you're replying to, but it sounds like in your comment you're reading "professor" as "full professor", which is not how I'd read it. I'd read it as basically "faculty member".
This is part of our research into drones for power line maintenance that we conduct at the University of Southern Denmark. You may have seen our previous work on drones that can recharge directly from power lines (https://www.youtube.com/watch?v=C-uekD6VTIQ), and this work is a direct extension of that.
Powerline inspection and maintenance are the primary use cases for this technology. And at least this particular system is in the early spinout process via https://www.ongrid.tech/
The gripper has several modes. There's a mode for charging the battery and providing holding force given AC powerline current, a mode for just holding the drone without charging given AC powerline current (if battery is full), and another mode where a small current (about 1W power) is taken from the battery and used to provide holding force in the case where there is no powerline current. Additionally, the gripper can be designed to fail open or fail closed, whichever is deemed appriate for the end-user.
The voltage of the powerline is not relevant since the charging principle is based on inductive coupling. So as long as you have a current above ~100A the harvester should work, irrespective of voltage. And high currents equal higher charging power.
To optimize charging time, the drone could perhaps analyze the magnetic fields to determine which line has the highest current to optimize charging time. But I would assume some sort of balancing is happening between the lines and phases.
The powerline used is a custom mockup with just 5V AC. But we have also landed on real powerlines. I think there's a video in the channel of the OP video.
