I recently watched IRON MAN 3 (yeah, that was pretty late), and instead of being dejected, for there came the end of such a marvelous series, I was bewildered by the level of technology (though fictional) that backed Tony. Imagine the possibilities that would open up if we could have something like the Iron Man suit.
I was excited, and the next day, after some search on the web, I came across these extremely tiny biosensors, called “Neural Dust”, invented by researchers at UC Berkeley. Now you may ask me, what’s with this ‘dust’ and Iron Man? Well, that will be clear in a moment.
So what is this Neural Dust?
“Neural dust is millimeter-sized devices operated as wirelessly powered nerve sensors. The sensors may be used to study or control the nerves and muscles and to remotely monitor neural activity. In practice, a medical treatment could introduce thousands of neural dust devices into human brains.”
In layman terms, it’s a wireless nano particle, which when implanted into the body, can read real time data from it, as well as control it to a certain extent. It could one-day help lead to next-generation brain-machine interfaces for controlling prosthetics, exoskeletons (like the suits of Iron Man) and robots, as well as “electroceuticals” to treat disorders of the brain and body.
Conventional electronic implants that connect to nerves rely heavily on wires that can inflame tissues over time. To give you an idea about how advanced these are from the present-day technology, have a look at the image below.
Now let us get into technicalities of the Neural Dust:
The new prototypes, are each roughly 3 millimeters long, 1 millimeter high and 4/5 of a millimeter thick. Each neural dust mote possesses a piezoelectric crystal that can convert mechanical power from ultrasonic pulses broadcast from outside the body into electrical power. The energy from these 60 ultrasonic pulses broadcast each second drives sensors and other electronics on the motes.
The piezoelectric crystals reflect some of the incoming ultrasonic pulses. Electronics in the neural dust motes can alter the pulses that get scattered outward, and so can wirelessly transmit data they gathered.
Neural dust motes were initially tested with the radio waves, to communicate with them and power them. But since radio waves are not good at reaching deep within the body, they turned over to ultrasonic waves, as evidently decades of ultrasonic imaging has revealed that ultrasonic pulses are very good at penetrating soft tissues.
Presently, the implants have been tested on rats, on the nerves and muscle fibers in the leg, and it has been found that they could record and transmit electrical data continuously.
Current status of research
The researchers are now working on miniaturizing the motes further, discovering more biocompatible materials to package them in so they can last in the body longer, and incorporating other sensors into them. Eventually motes could find use anywhere in the body, not just the nervous system.
The scientists are currently developing motes that can also electrically stimulate the body. If they are successful, then neural motes can not only monitor health, but also actively serve as electroceutical therapies to treat brain disorders such as epilepsy.
Challenges ahead
Right now the implants have been tested only on the peripheral nervous system, which covers the limbs, organs, muscles and joints.
If the motes are shrunk down to about 50 microns wide, roughly half the average width of a human hair, then it can not only be implanted in the Central Nervous System consisting of the brain and spinal cord, but can also function efficiently for a long period (about a decade). Still, electroceutical therapies may have many applications in the peripheral nervous system, such as bladder control or appetite suppression.
But soon enough we will witness a revolution, which will rewrite the history of the way man communicates with the machine. The term science “fiction” will be obsolete to the future generations.
Further Reading
http://www.cell.com/neuron/fulltext/S0896-6273(16)30344-0
– Sachin Goud
