Ok this is not about an episode, but you probably already guessed that. I found this article online about a team of physicists at the University of Dundee in the UK actually creating a functioning sonic screwdriver. The link for teh article is right below here. Just to clarify first though, the sonic screwdriver is the Doctor's tool for almost everything- opening doors, manipulating technology, scaring off bad guys- almost anything really. Now, check this out:
Those physicists were able to use energy from an ultrasound array to create a beam that carried the momentum to push away an object in its path and make the object rotate by creating a beam shaped like a helix. The physics of all this seems to be a bit of my head but I can explain the gist of it.
The researchers at the University of Dundee needed to create a large enough angular component of momentum or torque to cause the object the beam is pointing at to rotate and a powerful enough beam to force the object to levitate at the same time. According to the article, the researchers used a "1000-element ultrasound transducer array as an acoustic hologram" in order to generate vortex beams that would be strong enough to accomplish both of those tasks.
To make this even cooler, this sonic screwdriver can do more than just rotate and lift up a plastic disk. As Dr. Mike MacDonald from the Institute for Medical Science and Technology at the University of Dundee says, "â€œThe â€˜sonic screwdriverâ€™ device is also part of the EU-funded Nanoporation project where we are already starting to push the boundaries of what ultrasound can do in terms of targeted drug delivery and targeted cellular surgery,...It is an area that has great potential for developing new surgical techniques, among other applications, something which Dundee is very much at the forefront of...".
All in all, this is a pretty cool advancement not just in the world of physics but also in the medical field and it had some basis in the technology of one of the most beloved science-fiction heroes to appear on television.