The term nanotechnology refers to engineering on a molecular scale, measured with units like nanometers, which consist of 1 billionth of a meter (a sheet of newspaper is about 100,000 nanometers thick). These microscopic dimensions have the potential to enact major changes in the diagnosis of diseases, building of medical instruments, and creating ‘smart’ textiles and materials. But potentially the most intriguing possibility, straight out of science fiction, is the potential for implants which supplement or even supplant human brain activity.

Nanotech has already been the subject of substantial neurological research. In 2015, Harvard scientists implanted a nanofiber mesh into subject mice designed to monitor brain activity on a neuron-by-neuron level. While neural implants do exist already on a limited basis, nanotech allows for soft, flexible materials that don’t agitate fragile brain tissue. With these more pinpointed brain-scanning tools, scientists expect to expand our understanding of how the individual parts of the brain work, with an eye towards engineering solutions for neurological conditions like Parkinson’s disease.

The ability to monitor a large number of neurons at once would amount to a revolutionary leap in neurologists’ and researchers’ ability to study the brain. The latest brain-mapping developments have plotted out the brain structure of a fruit fly, continuing (but not completing) the work of figuring out precisely which parts of their tiny brains are used for certain tasks. To do the same for human brains, which possess over one million times the number of neurons of a fly’s, nanotech harbors the best likely solution.

Research towards that end is already underway. The U.S. government has made a $100 million commitment to supporting The Brain Initiative, an ambitious project that hopes to utilize nanotechnology to create a detailed plot of our brains that will serve as a roadmap to ending neurological disorders. Probing the brain in this fashion will require nano-equipment that hasn’t yet been invented, so the seed money provided is part of a long-term support track that hopes to see results in about a decade.

To some observers, the possibilities of neural nanotech go far beyond curing diseases. These forecasters see the future of nanotechnology as inextricably linked to the ultimate fate of the human race. Futurist, computer scientist and author Ray Kurzweil has written extensively about humanity’s tech-infused future, particularly the potential of intelligent nanobots to supplement or even replace brain functions, bringing about a new form of elevated humanity. It sounds like science fiction, but the enhancement of human brain functions with artificial intelligence looks to be well within the realm of possibility.

Kurzweil’s writings have frequently centered around the concept of the singularity, a future point in time where AI overtakes human intelligence and brain functions can be uploaded to nanomachines. This creates an intelligent, literal ‘cloud’ of nanobots holding within their microscopic circuits the sum of human knowledge. In this technofuture, human mind functions will take place entirely within machines, allowing us to upload our thoughts and memories into an amorphous cloud of nanobots which can survive in any conditions, essentially allowing us to ‘live’ forever.

It’s a thrilling and potentially terrifying possibility, so naturally these ideas have attracted a good deal of criticism. Notably, as fellow futurist Paul Davies wrote in a review of Kurzweil’s The Singularity is Near, the idea that growth will always happen exponentially is an often fallacious way of thinking. The predictions of the singularity assume that the growth (or shrinking, as it were) of nano tech will proceed at a rapidly multiplying rate towards one particular end.

As anyone who has attempted to predict the course of human events can tell you, this way of thinking will generate just one of many potential futures. Predicting the future, no matter how well informed you are, is often a matter of claiming to know the unknowable. The fate of nano tech, much like humanity as a whole, is still very much up in the air.

Projects like the Brain Initiative are working on a long-term schedule, with results so far off in the future that they may consist of answers to questions we haven’t even thought up yet. Can nanobots offer us a way to live forever, in the cloud? Can we say that our species even still exists when we’re no longer connected to actual, breathing bodies?  These are dizzying possibilities, ones that will require new evaluations about what it means to be human.

These questions are more relevant than one might think. Within a generation, we may be debating whether nanotech is an ethical field of study, the way similar arguments have been made against cloning and AI. Of course, there is still a long road ahead for advanced nanotech. We might be heading towards an era of ascended superhuman minds, but for now, our primitive brains will have to figure it out how to make it happen.