PDF Basket
Officially, Lydéric Bocquet is an expert in nanofluidics at the French National Centre for Scientific Research and the École Normale Supérieure in Paris. But if you ask him, he’ll give you a more prosaic job title.
“Ultimately, I’m a plumber of the infinitely small,” he says, “carefully watching fluids as they flow through the smallest channels imaginable.”
Nanofluidics is the frontier where the continuum of fluid mechanics meets the discrete atomic nature of matter. “In nanofluidics, we study the behaviour, manipulation and control of fluids that are confined to structures typically 1–100 nanometres,” explains Bocquet.
This is hundreds of times smaller than the width of a human hair. When confined to such tiny structures, fluids tend to act differently, and can even exhibit new properties – attracting the interest of researchers such as Bocquet.
Nanofluidics is also something readily found in nature, including within our very own bodies. As Bocquet elaborates: “From our kidney’s filtration system to our brain’s neurons and synapses, examples of nanofluidics can be found everywhere.”
According to Bocquet, understanding nanofluidics is the key to replicating it for use in artificial applications – the goal of the SHADOKS project, which was funded by the European Research Council. Headed by Bocquet, the project is leading an effort to not only increase our understanding of nanofluidics, but use this new-found knowledge to build ionic machines.
Two bananas a day of efficiency
Ionic machines are essentially artificial devices that operate similarly to the human brain. Once confined to the pages of science fiction, this concept is starting to become a reality.
As Bocquet explains, nanofluidic computing aims to mimic the brain’s incredible energy efficiency with regard to information processing. With its billions of neurons connected through trillions of synapses, the brain optimises the way information flows while avoiding the costly and constant shuttling of data between the processor and memory – a hallmark of classic computer architecture.
“The brain is a supercomputer that can be powered on just two bananas a day – making it much more efficient than any actual computer,” adds Bocquet.
The SHADOKS project aimed to develop basic computer components based on nanofluidic principles. Researchers created an ionic machine capable of mimicking the brain’s efficient flow of information, using ions that move through fluids and carry and store information.
“It is the first brick of the edifice but such nanofluidic computing promises lower energy consumption, hardware-level plasticity and multiple information carriers,” remarks Bocquet.
A cabinet of nanofluidic curiosities
While busy working on the ionic machine, Bocquet and his team also made several other important discoveries – what he refers to as a “cabinet of nanofluidic curiosities.”
One such finding pertains to how water flows within carbon-based nanochannels such as the carbon nanotubes used in sports equipment, body armour and vehicles. “It has long been believed that water confined to a carbon nanotube flows up to 10 000 times faster than it would flow in an unconfined space,” adds Bocquet.
In previous experiments, Bocquet had shown that the friction of the water along a nanotube wall behaves abnormally. During the SHADOKS project, he and his team were finally able to explain why. “It turns out that the answer is an unconventional quantum friction effect that is unique to the properties of carbon nanotubes,” explains Bocquet.
Bocquet says this link between hydrodynamics and quantum physics opens the door to a wide range of possible applications, including coupling water transport to electronic transport.
Opening the freshwater floodgates
Another item in Bocquet’s cabinet is the use of nanofluidics in desalination and water filtration. “Because our proposed solution uses electric fields instead of pressure, it can be easily scaled, and thus has the potential to significantly increase the world’s access to freshwater,” he remarks.
Several patents have been filed for the new nanofluidic-based filtration/desalination system, and Bocquet intends to launch a start-up to advance the concept towards commercialisation.
According to Bocquet, this development, together with its work on ionic machines and other areas of research, is proof positive that the SHADOKS project has established a new paradigm in the context of nanofluidics. “I am convinced that the groundbreaking science that came out of this project will lead to groundbreaking innovation in the years to come,” he concludes.