Tag Archives: Helge Lemmetyinen

Electricity without a current

My imagination fails at the thought of electricity without a current luckily there’s a consortium of scientists at Finland’s Tampere University of  Technology (TUT) who have no trouble with their imaginations, according to the Sept. 12, 2012 news item on Nanowerk (Note: I have removed a link from the following excerpt),

The Academy of Finland has granted €1.6 million to a consortium based at Tampere University of Technology (TUT) under the “Programmable Materials” funding scheme. The project runs from 1 September 2012 to 31 August 2016 and is entitled “Photonically Addressed Zero Current Logic through Nano-Assembly of Functionalised Nanoparticles to Quantum Dot Cellular Automata” ( PhotonicQCA).

The Sept. 12, 2012 news release from TUT which originated the news item explains the ideas and work which support the notion of electricity without current,

The key idea behind the project is the so-called quantum dot cellular automaton (QCA). In QCAs, pieces of semiconductor so small that single electronic charges can be measured and manipulated are arranged into domino like cells. Like dominos, these cells can be arranged so that the position of the charges in one cell affects the position of the charges in the next cell, which allows making logical circuits out of these “quantum dominos”. But, no charge flows from one cell to the next, i.e. no current. This, plus the extremely small size of QCAs, means that they could be used to make electronic circuits at densities and speeds not possible now. However, realisation of the dots and cells and making electrical connections to them has been a huge challenge.

Professors Donald Lupo from Department of Electronics, Mircea Guina and Tapio Niemi from Optoelectronics Research Centre (ORC), and Nikolai Tkachenko and Helge Lemmetyinen from Department of Chemistry and Bioengineering, want to investigate a completely new approach. They want to attach tailor-made molecules, optical nanoantennas, to the quantum dots, which can inject a charge into a dot or enable charge transfer between the dots when light of the right wavelength shines on them. This concept will be combined with the expertise at TUT’s Optoelectronics Research Centre concerning “site-specific epitaxy”, i.e. growing the quantum dots in the right place using nanofabrication techniques, which would enable a solid-state technology platform compatible with standard electronic circuits. If this works, then someday QCAs could be written and read with light.

Project coordinator, Professor Donald Lupo says: “As far as we can tell, no one has ever tried anything like this before. It’s a completely new idea. It was our excellent inter-departmental communication that identified a unique combination of know-how that let us come up with this concept. It’s highly risky because of many technological challenges, but the potential is amazing; being able to get rid of electrical connections and write and read nanoelectronic circuits using only light would be a huge breakthrough”.

Reading the Programmable Materials page on the Academy of Finland website provided some clues for what they hope to achieve with this ‘electricity’ project is all about,

The FinnSight 2015 report published in 2006 underscores the fact that materials research is a cross-disciplinary exercise: new materials are increasingly being developed on a multidisciplinary platform. The report also urges Finnish materials research to step up its efforts to explore the more advanced properties of new materials that are still partly unknown.

Most new materials today are typically static by nature. They are composed of components that have a specific function or quality, but they do not respond to their environment as such. Programmable materials, by contrast, are composed of components that respond in a specific, programmed way to environmental stimuli and signals. Depending on the initial state or code of these components, it is possible to produce various complex, even macroscopic, structures in a controlled way.

Programmable materials represent a new emerging research field in which Finland can play a pioneering role. The programmable properties of different materials are continuing to develop with advances in such fields as nano- and biotechnology, and programmable materials may completely revolutionise applications of functional materials.

Materials programming is an emerging, all-new field of research. The aim of this programme is to work with the best international research teams and solidify Finland’s position at the international forefront of research. The strongest countries in this field include the United States, Japan, Russia, India and certain European countries. In addition, China has a strong emerging materials research field.

I threw in that last paragraph because I find their analysis of the international scene quite interesting and notice they list three of the BRICS (Brazil, Russia, India, China, ans South Africa) countries as leaders in this emergent field.

Getting back to this specific ‘electricity’ project, it sounds as if they’re working on an electrical component which could be made to operate when a light is shone on it in a process that reminiscent of photosynthesis (Wikipedia essay on photosynthesis) where a plant converts light into chemical energy.