A physicist has developed a new theory of thermodynamics to describe the microscopic world. It explains the astonishing efficiency of biological motors in our cells, improves the efficiency of chemical reactions and reveals the concrete role played by this abstract concept: information.
At the beginning of the 19th century, steam engines began to move trains and industrial power machines. Thermodynamics at that time developed theoretical tools to analyse their energy balance and improve their efficiency. Two centuries later, a physicist from the University of Luxembourg invented novel thermodynamics to study microscopic phenomena. His work and the contributions of researchers from all over the world have led to a better understanding of fundamental biological, chemical and electronic phenomena, and to the imagination of how to push back the limits of their efficiency.
Efficiency and power, simultaneously
Massimiliano Esposito has discovered a surprising principle: while it is impossible to maximise the efficiency of an engine and its power simultaneously, as motorists are well aware, it is possible to achieve the equivalent in chemical reactions.
“Traditional chemistry normally proceeds rather slowly,” explains the researcher. “Just as in cooking, ingredients are added to containers, mixed, cooked and then left to set. But it can be done differently, by bringing in constant flows of reagents through tubes. This results in rapid reactions.”
Esposito analysed these chemical reactions as thermal machines and showed that it is indeed possible to produce molecules both abundantly and efficiently – an impossible optimum in conventional thermodynamics.
The secret is to work in a different regime. Standard thermodynamics is normally concerned with situations close to equilibrium or a stationary regime characterised by slow and constant flows. Massimiliano Esposito, on the other hand, has developed a theory of out-of-equilibrium thermodynamics: it describes abrupt changes, and in these conditions, it enables to go beyond the usual limits of efficiency.
Exploring such a regimen naturally leads to the microscopic world, because the smaller the system, the faster and stronger it reacts: the air in the centre of a balloon, for example, is protected from external influences by numerous layers of air. On the contrary, a molecule constituting a nanoparticle is very close to the surface and participates fully in the reactions.
Cellular railway
Equipped with the concepts he has been developing for the last ten years, Massimiliano Esposito tackles a wide variety of problems. Recently, he has been studying the astonishing efficiency of kinesins, molecular motors charged with transporting biochemical structures inside living cells. Like locomotives, these proteins move along microtubules – filaments acting as rails – towing their cargo behind them.
His work suggests that collective effects may explain the efficiency of these phenomena essential to life. Using simplified models, he has shown that the efficiency of these motors increases tenfold when they operate in a synchronised fashion, like rowing machines. The total power is then far greater than the sum of the individual motor powers.
Confronting a demon
His concepts have also made it possible to elucidate a famous mystery – or paradox – of physics: Maxwell’s Demon, an imaginary devil who would sort gas particles according to their speed in order to cool a gas without consuming energy, in flagrant contradiction with the second law of thermodynamics. One of his articles inspired a Finnish team to build a real Demon based on a pair of tiny electronic structures called quantum dots. In this experiment, the first quantum dot plays the role of the demon: it influences the number of electrons trapped in the second without expending any energy. In doing so, it cools its environment, as if a river were beginning to flow back towards its higher source.
This sacrilegious experiment roughs up the laws of thermodynamics, explains the physicist, but it does not contravene them. However, it is crucial to take into account not only energy balances but also information transfers, because information is not free and has an energy cost that can be quantified. These considerations are not just imaginary demons but are at the basis of information theory, which is crucial in computing and telecommunications.
The importance of solid foundations
Like thermodynamics in its early days, Massimiliano Esposito’s work is very theoretical. But they are often taken up by scientists who tackle concrete problems: biologists studying cells, chemists seeking to optimise reactions, or engineers making devices to generate electricity in satellites thanks to the temperature differences in space.
“The aim of my work is to develop a solid and reliable theoretical basis that is useful to other specialists. But I also want to encourage links between physicists, biologists and engineers. The solutions developed by nature are often extremely effective. It is up to us to understand why.”
About the European Research Council (ERC)
The European Research Council, set up by the EU in 2007, is the premiere European funding organisation for excellent frontier research. Every year, it selects and funds the very best, creative researchers of any nationality and age, to run projects based in Europe. The ERC offers four core grant schemes: Starting, Consolidator, Advanced and Synergy Grants. With its additional Proof of Concept grant scheme, the ERC helps grantees to bridge the gap between grantees’ pioneering research and early phases of its commercialisation. https://erc.europa.eu
More about Massimiliano Esposito & thermodynamics
September 16, 2019
Energy is not generated; it is only changed. The physicist Riccardo Rao has dedicated his energy to find out more about the thermodynamic costs of these changes in biologically-inspired models.
December 14, 2017
Massimiliano Esposito works in one of the few research fields that still use a blackboard, pen and paper: theoretical physics. After research stays in Belgium and the US, the Italian-become-Luxembourg-national returned to Luxembourg, to take up his FNR ATTRACT Fellowship. Five years later as the ATTRACT funding concludes and he embarks on a prestigious ERC-funded project, Massimiliano spoke to us about how his team is stronger than ever and how lucky he feels that he can focus on his research and put funding concerns aside.
More features in this series
December 3, 2020
A mathematician develops new algorithms that allow the analysis of encrypted data without ever having to decipher it—a crucial point to ensure their confidentiality.
November 26, 2020
Anja Leist wants to find out how to resist the decline of our cognitive abilities in old age. Her international research has already achieved a first result: improving education helps prevent problems occurring decades later.
November 19, 2020
Politicians and voters in the countries of Ex-Yugoslavia are still referring to conflicts which happened two decades ago. A political scientist wants to understand why and how to let go of the past.
November 12, 2020
A chemist wants to use solar energy to produce hydrogen from water. His idea? To draw inspiration from the molecules that allow plants to grow and animals to breathe.
October 29, 2020
A physicist invented a new method to authenticate objects by using the strange properties of liquid crystals. He also spun them into smart elastic bands for applications in soft robotics and wearable technologies.
October 26, 2020
Most scientists need no introduction to the prestigious funding schemes offered by the European Research Council – they have been described as one of the success stories of the European research funding framework and have become a global beacon of excellence in blue sky research. Luxinnovation can help researchers in Luxembourg with their ERC proposal.
October 22, 2020
Physicist Daniele Brida develops ultrafast lasers to follow in slow-motion chemical reactions and the inner working of electronic devices. This new kind of microscope allows the observation of phenomena at the nanoscale that were until now just too fast to be seen – improving photovoltaics and electronics devices.
October 15, 2020
Chemical compounds can have several stable forms – with dramatic consequences. A physicist at the University of Luxembourg can predict when this can occur: he has develop methods to precisely calculate the stability of molecules. These tools are now used by hundreds of scientists worldwide. They could also help understand why the new coronavirus is so contagious.
October 8, 2020
Countless microorganisms live peacefully in our body, but they also can be involved in many diseases. To find out exactly what role they play, a biologist has given himself a Herculean task: survey all the biomolecules produced by the microbes residing in our guts.
October 1, 2020
Machine learning algorithms seem all-powerful, but still function passively: they merely analyse the data they are fed with. Björn Ottersten makes them smarter by letting them actively probe their environment. His work aims to improve sensors of self-driving cars, sharing of mobile bandwidth and Internet traffic.
The ERC series is written by Daniel Saraga. The purpose of this ERC series is to showcase the high quality of research in Luxembourg, and how it is also attracting prestigious international funding.