Scientists at Johannes Gutenberg University Mainz (JGU) and the University of Erlangen-Nuremberg are working on a heat engine that consists of just a single ion. Such a nano-heat engine could be far more efficient than, for example, a car engine or a coal-fired power plant.
A single trapped ion in a linear Paul trap with special geometry: The heat engine is being realized by the divergent bars; the squeezing is being caused by establishing special electrical fields.
source: AG Quantum, JGU
A usual heat engine transforms heat into utilizable mechanical energy with the corresponding efficiency of an Otto engine amounting to only about 25 percent, for instance. The proposed nano-heat engine consisting of a single calcium ion would be much more efficient. The main aim of the research being conducted is to better understand how thermodynamics works on very small scales. A pilot prototype of such a single-ion heat engine is currently being constructed at Mainz University.
As the physicists explain in an article recently published in the journal Physical Review Letters, the efficiency of heat engines powered by thermal heat reservoirs is determined by the second law of thermodynamics, one of the fundamental concepts in physics. It was as far back as 1824 that Frenchman Nicolas Carnot calculated the maximum possible efficiency limit of such engines, now known as the Carnot limit. In the case of the newly proposed nano-heat engine, the scientists have been theoretically able to exceed the classic Carnot limit by manipulating the heat baths and exploiting nonequlibrium states.
Calculations and simulations made about a year ago showed for the first time that the thermo-dynamic flow in an internal combustion engine could be reproduced using individual ions. The idea was to use a calcium 40 ion, which has a diameter a million times smaller than that of a human hair, for this purpose. "Individual ions can basically act as the piston and drive shaft or, in other words, represent the entire engine," explained Johannes Roßnagel of the Quantum, Atomic, and Neutron Physics (QUANTUM) work group of the JGU Institute of Physics. Individual ions have already been captured in Paul traps and, using laser beams and electrical fields, not only cooled and heated but also compressed.
"This means we are able to manipulate the pulse location distribution for optimum efficiency," added Roßnagel. "Exceeding the Carnot limit for a standard heat engine thus does not violate the second law of thermodynamics but instead demonstrates that the use of specially prepared, non-thermal heat reservoirs also makes it possible to further improve efficiency." In their publication, the physicists calculated the general Carnot limit for this situation. As the mechanical capacity of a single ion machine is extremely low, it can probably only be used in heating or cooling nano systems.
The intention is now to actually develop the proposed single ion heat engine in initial experiments and construct a prototype in the laboratory.
source: AG Quantum, JGUhttp://www.uni-mainz.de/bilder_presse/08_physik_quantum_waermekraftmaschine_2.jpg
source: AG Quantum, JGUFurther information:
Identifying New Sources of Turbulence in Spherical Tokamaks
30.11.2015 | Princeton Plasma Physics Laboratory
Graphene microphone outperforms traditional nickel and offers ultrasonic reach
27.11.2015 | Institute of Physics
Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular chain of events that enables the cells to make “sounds” on their own, essentially “practicing” their ability to process sounds in the world around them.
The researchers, who describe their experiments in the Dec. 3 edition of the journal Cell, show how hair cells in the inner ear can be activated in the absence...
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
30.11.2015 | Event News
25.11.2015 | Event News
17.11.2015 | Event News
30.11.2015 | Trade Fair News
30.11.2015 | Trade Fair News
30.11.2015 | Trade Fair News