Advances in brain imaging and neural activity detection technologies, such as fMRI and EEG, have allowed us to learn much about the brain over the years, and neural implants have offered the ability to stimulate and all but control activity in certain parts of the brain. However, these brain-computer interfaces are limited in that they offer finite resolution, are hard to apply to many brain regions, and usually can only stay directly connected to the brain for a short period of time due to their invasiveness.

Engineers at the University of California, Berkeley, have proposed an ultra-small, ultrasound-based neural recording system that they call “neural dust”. Neural dust consists of thousands of sensors that are 10-100 micrometers in size containing CMOS circuits and sensors to detect and report local extracellular electrophysiological data. The neural dust is powered by ultrasonic waves via a transducer that is implanted just below the dura. The sub-dural unit also interrogates the neural dust and sends information to another receiver outside the body.

If neural dust becomes a reality, it could give us a much higher resolution look at what is going on inside the brain, as it will be able to record from thousands of sites within the brain, in contrast to the hundreds of channels that current technology allows. Moreover, because these tiny sensors are literally the size of dust particles, they could cause far less damage to the surrounding brain tissue and could stay embedded in the brain for long periods of time.

Journal article: arXiv: Neural Dust: An Ultrasonic, Low Power Solution for Chronic Brain-Machine Interfaces

(hat tip: Gizmodo)