MIT Technology Review: How Smart Dust Could Spy On Your Brain

This is an article from the MIT Technology Review website called How Smart Dust Could Spy On Your Brain which is based on research being conducted at the University of California Berkeley.  The future applications of this technology will be to allow higher resolution brain scans and shows potential as a medium for brain-machine interfaces (BMI).  It will be interesting to see where this research goes.


The real time monitoring of brain function has advanced in leaps and bounds in recent years. That’s largely thanks to various new technologies that can monitor the collective behaviour of groups of neurons, such as functional magnetic resonance imaging, magnetoencephalopathy and positron emission tomography.

This work is revolutionising our understanding of the way the brain is structured and behaves. It has also lead to a new engineering discipline of brain-machine interfaces, which allows people to control machines by thought alone.

Impressive though these techniques are, they all suffer from inherent limitations such as limited spatial resolution, a lack of portability and extreme invasiveness.

Today, Dongjin Seo and pals at the University of California Berkeley reveal an entirely new way to study and interact with the brain. Their idea is to sprinkle electronic sensors the size of dust particles into the cortex and to interrogate them remotely using ultrasound. The ultrasound also powers this so-called neural dust.

Each particle of neural dust consists of standard CMOS circuits and sensors that measure the electrical activity in neurons nearby. This is coupled to a piezoelectric material that converts ultra-high-frequency sound waves into electrical signals and vice versa.

The neural dust is interrogated by another component placed beneath the scale but powered from outside the body. This generates the ultrasound that powers the neural dust and sensors that listen out for their response, rather like an RFID system.

The system is also tetherless–the data is collected and stored outside the body for later analysis.

That gets around many of the limitations. The system is lower power, can have a high spatial resolution, and it is easily portable. It is also rugged and can potentially provides a link over long periods of time. “A major hurdle in brain-machine interfaces (BMI) is the lack of an implantable neural interface system that remains viable for a lifetime,” say Seo and co.

The difficulty is in designing and building such a system and today’s paper is a theoretical study of these challenges. First is the problem of designing and building neural dust particles on a scale of roughly 100 micrometres that can send and receive signals in the harsh, warm and noisy environment within the body.

That’s why Seo and co have chosen ultrasound to send and receive data. They calculate that the power required to use electromagnetic waves on the scale would generate a damaging amount of heat because of the amount of energy the body absorbs and the troubling signal-to-noise ratios at this scale.

By contrast, ultrasound is a much more efficient and should allow the transmission of at least 10 million times more power than electromagnetic waves at the same scale.

Next is the problem of linking the electronics to the piezoelectric system that converts ultrasound to electronic signals and vice versa. Ensuring that the system works efficiently will be tricky given that it has to be packaged in an inert polymer or insulator film (which must also expose the recording electrodes to nearby neurons).

Finally, there is the challenge of designing and building the interrogation system that generates the ultrasound to power the entire array but at a low enough power to avoid heating skull and the brain.

On top of all this is the additional challenge of implanting the neural dust particles in the cortex. Seo and co say this can probably be done by fabricating the dust particles on the tips of a fine wire array, held in place by surface tension, for example. This array would be dipped into the cortex where the dust particles become embedded.

That’s an ambitious vision that is littered with challenges beyond the state-of-the-art. However, the team has a strong background in nanoelectromechanical systems and in the interface between electronic systems and cells.

Indeed, one of the authors, Michel Maharbiz, developed the world’s first remotely controlled beetle a few years ago, a development that was named one of the top 10 emerging technologies of 2009 by Technology Review.

These guys are clearly not afraid to take on big challenges. It’ll be interesting to see how they fare.

Ref: Neural Dust: An Ultrasonic, Low Power Solution for Chronic Brain-Machine Interfaces


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Just a Another Definition of “The Singularity”

There are plenty of definitions of the singularity out there and I don’t plan to post any more of these, but I thought this one (from WhatIs)was worth having on Dawn of Giants.  

Singularity (the)

Part of the Nanotechnology glossary:

The Singularity is the hypothetical future creation of superintelligent machines. Superintelligence is defined as a technologically-created cognitive capacity far beyond that possible for humans. Should the Singularity occur, technology will advance beyond our ability to foresee or control its outcomes and the world will be transformed beyond recognition by the application of superintelligence to humans and/or human problems, including poverty, disease and mortality.

Revolutions in genetics, nanotechnology and robotics (GNR) in the first half of the 21stcentury are expected to lay the foundation for the Singularity. According to Singularity theory, superintelligence will be developed by self-directed computers and will increase exponentially rather than incrementally.

Lev Grossman explains the prospective exponential gains in capacity enabled by superintelligent machines in an article in Time:

“Their rate of development would also continue to increase, because they would take over their own development from their slower-thinking human creators. Imagine a computer scientist that was itself a super-intelligent computer. It would work incredibly quickly. It could draw on huge amounts of data effortlessly. It wouldn’t even take breaks to play Farmville.”

Proposed mechanisms for adding superintelligence to humans include brain-computer interfaces, biological alteration of the brain, artificial intelligence (AI) brain implants and genetic engineering. Post-singularity, humanity and the world would be quite different.  A human could potentially scan his consciousness into a computer and live eternally in virtual reality or as a sentient robot. Futurists such as Ray Kurzweil (author of The Singularity is Near) have predicted that in a post-Singularity world, humans would typically live much of the time in virtual reality — which would be virtually indistinguishable from normal reality. Kurzweil predicts, based on mathematical calculations of exponential technological development, that the Singularity will come to pass by 2045.

Most arguments against the possibility of the Singularity involve doubts that computers can ever become intelligent in the human sense. The human brain and cognitive processes may simply be more complex than a computer could be. Furthermore, because the human brain isanalog, with theoretically infinite values for any process, some believe that it cannot ever be replicated in a digital format. Some theorists also point out that the Singularity may not even be desirable from a human perspective because there is no reason to assume that a superintelligence would see value in, for example, the continued existence or well-being of humans.

Science-fiction writer Vernor Vinge first used the term the Singularity in this context in the 1980s, when he used it in reference to the British mathematician I.J. Good’s concept of an “intelligence explosion” brought about by the advent of superintelligent machines. The term is borrowed from physics; in that context a singularity is a point where the known physical laws cease to apply.


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