Elon Musk, perhaps the world's most famous entrepreneur,
is sometimes referred to as "the Trump of technology"— not for political reasons,
but because of his habit of making, at short notice, spectacular pronouncements that stretch the bounds of credibility.
On July 16th he was at it again, unveiling a new type of brain-machine interface (BMI).
If human beings do not enter a symbiosis with artificial intelligence (AI), he declared, they are sure to be left behind.
And he, the announcement implied, was going to be the man who stopped that happening.
Connecting brains directly to machines is a long-standing aspiration. And it is already happening, albeit in a crude way.
In deep-brain stimulation, for example, neurosurgeons implant a few electrodes into a patient's brain in order to treat Parkinson's disease.
Utah arrays, collections of 100 conductive silicon needles, are now employed experimentally to record brain waves.
A team at the University of Washington has built a "brain-to-brain network"
that allows people to play games with each other using just their thoughts.
And researchers at the University of California, San Francisco, have captured neural signals from people as they talk,
and have then turned that information, via a computer, into intelligible speech.
As with all things Musk-related, Neuralink is much more ambitious. The firm does not just want to develop a better BMI.
Its aim is to create a "neural lace", a mesh of ultra-thin electrodes that capture as much information from the brain as possible.
Unsurprisingly, hurdles abound. The electrodes needed to do this must be flexible,
so that they do not damage brain tissue and will also last for a long time.
They have to number at least in the thousands, to provide sufficient bandwidth.
And to make the implantation of so many electrodes safe, painless and effective, the process has to be automated,
much like LASIK surgery, which uses lasers to correct eyesight.
Neuralink does indeed seem to have made progress towards these goals.
Its presentation, at the California Academy of Sciences, in San Francisco,
included videos of a neurosurgical robot that is best described as a sewing machine.
This robot grabs "threads" (films, containing electrodes, that measure less than a quarter of the diameter of a human hair),
and shoots them deep into the brain through a hole in the skull. It is capable of inserting six threads, each carrying 32 electrodes, per minute.