Can quantum physics help with mind reading

What can Neuralink's brain implant do that others can't?

Elon Musk has a pig. Last weekend, the billionaire and Tesla founder presented the latest developments from his neurotechnology start-up Neuralink. The highlight of the short video presentation was Gertrude: a pig in whose brain the researchers implanted a microchip that can recognize certain brain waves. Whenever Gertrude touched something with her trunk, for example food or the hand of her carer, a beep could be heard. "He's like a Fitbit in his head with tiny wires," Musk said over the chip called Link V.09.

If Musk and the Neuralink scientists have their way, Gertrude should be just the beginning. The company is working on a brain-machine interface that will one day alleviate brain damage, body paralysis, visual disturbances and depression, as well as increase the performance of the human brain. And you should be able to control video games with it. The first hurdle for tests on humans has now been cleared, said Musk. In July, the American FDA classified the chip as a "groundbreaking device," which could accelerate approval.

But how important is the Neuralink interface really? An implant, the tiny electrodes of which are attached to specific locations in the brain, record or trigger nerve signals there and forward the data to a computer, sounds like science fiction, but from a medical point of view it has long been a reality. The technology enables completely paralyzed people to move a prosthetic arm or the cursor on a screen with the power of their thoughts alone. Targeted stimulation from brain pacemakers can help with Parkinson's and even restore some eyesight to blind people.

The greatest innovation in materials research

Since the beginning in the 1970s, Brain Computer Interfaces, or BCI for short, have made great strides, especially in the past 20 years. The technology describes the connection between the brain and a computer by measuring electrical activity: the nerve cells in the brain, the neurons, communicate with each other via short electrical signals. Whenever we think, feel or move something, neurons are activated in different areas of the brain. This electrical activity can be measured. For example with electrodes on the scalp as in electroencephalography (EEG). Or invasively through the direct connection of electrodes to parts of the brain, such as the motor cortex, which controls movements.
"So far, there are not too many implants with more than 1000 canals."
(Thomas Stieglitz, Professor of Medical Microtechnology)

The Neuralink chip is also implanted directly into the brain. "I am impressed by how quickly Neuralink has come up with the latest technology," says Thomas Stieglitz, Professor of Medical Microtechnology at the Institute for Microsystems Technology at the Albert Ludwig University of Freiburg. Only four years after it was founded, the start-up developed an interface that, from a purely technical point of view, can compete with established systems - provided that it actually works as announced by Elon Musk. The San Francisco-based company has not yet published a study that has been checked by independent researchers, which led to criticism from researchers last year.

Neuralink's Implant Link V.09 is about the size of a cent coin, on the underside there are up to 1024 electrodes, which are connected to the brain tissue and can both read and emit impulses. The data transfer to the computer works via Bluetooth, the implant is charged via induction like a smartphone or smartwatch. "So far, there aren't too many implants with more than 1000 canals," says Stieglitz. For this large number of electrodes, "watertight connections made of highly sensitive microtechnology" are required, which makes the system interesting in terms of materials research alone. And because the Link V.09 transmits wirelessly and is also incorporated into the skull and sealed there, two problems of many BCIs are avoided: the risk of infection, which is always increased when cables protrude from the skull. And the constant medical monitoring of the connected equipment.

This is what distinguishes Neuralink's BCI from existing invasive techniques such as the Utah Array, which has been developed for more than two decades and has also been used in individuals for a number of years, for example by BrainGate at Brown University. It is an implant with around 100 comparatively rigid electrodes that are located in the brain tissue and send data by cable to a receiver on the head. Because scar tissue forms around the electrodes, they may deteriorate over time. Therefore the system has to be checked regularly. In addition, there is always the risk of microbleeding. Neuralink does not only want to avoid this risk with particularly thin and elastic electrodes. A specially developed robot is to place the electrodes in such a way that they do not damage any blood vessels. The whole process should take just an hour under local anesthesia, said Elon Musk.