Separate molecule¹ is smallest electric engine ever

For the first time, an electric engine has been made from a single molecule¹. At 1X10e-09 meter long, that makes the organic² compound³ the smallest electric engine ever. Its agents putting into existence the idea to put forward their design to Guinness World records, but the small engine could also have good uses, such as pushing liquid (or gas) through narrow pipes in "lab-on-a-chip" apparatus.

Molecules¹ have previously converted energy from light and chemical reactions into directed motion like rolling or moving up and down. Electrics has also set an oxygen molecule¹ turning as by chance. But controlled, electrics-driven motion – necessary for an idea to be ordered as a engine – had not yet been observed in a single molecule¹.

To house this, E. Charles Sykes at Tufts University in Boston and persons having like-position turned to asymmetric⁴ butyl⁵ methyl⁶ sulphide⁷, a sulphur⁸ atom with a chain of four carbons on one side and a only one carbon atom on the other. They fixed the molecule¹ to a copper plane via the sulphur⁸ atom, producing a uneven, horizontal "propeller⁹" that is free to go round about the upright copper-sulphur⁸ join (see outline). Over the molecule¹ they placed a metal needle a few molecules¹ wide at its endbit. When they came in great numbers a current from this endbit, through the molecule¹, to the conductive copper under, the molecule¹ converted the electrics energy into rotational¹⁰ energy. It bounced around in condition of shaking dances about 50 times a second.

Because the propeller⁹ is asymmetrical¹¹, there are two ways it can be adjusted with respect to the copper. In one make adjustment – but not the other – the molecule¹'s dances were not random but slightly had a tendency in a certain direction in the direction of rotating going round left to right, allowing the researchers to put it in order as an engine.

It is not clear why the tendency in a certain direction takes place but Sykes suspects that a natural asymmetry¹² in the endbit of the metal needle could give an account of why it only takes place in one molecule¹ adjustment. If accepted by Guinness, the engine will be a record smasher. The current world-record keeper for the smallest electric engine is an over-size man by comparison, composed of two 200x10e-09 metre long black nanotubes¹³. Current running through these nanotubes¹³ pushes drops of made-liquid by heat metal from the outside of one pipe to the other. Sykes hopes to get ready his very small engine to fight the rubbing that slows liquid (or gas) moving liquid in nanosized pipes. Kevin Kelly of Rice University in Houston, Texas, who was not involved in the work, points out that if electrics energy move across does differently depending on the form of the molecules¹, this could have follow-ups for the design of molecule¹-scale electrics circuits¹⁴, which could be used in very small sensors or computer bits.

http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2011.142.html

1  molecule  The smallest unit making up a chemical ELEMENT or COMPOUND which has the same properties as the substance in the mass, and has the power of independent existence, a structure of two or more ATOMS.   Go back

2  organic  To do with organic chemistry.   Go back

3  compound  A compound thing, sp. a CHEMICAL COMPOUND.   Go back

4  asymmetric  Having no SYMMETRY.   Go back

5  butyl  The OPEN-CHAIN ALKYL RADICAL C4H9, got from BUTANE.   Go back

7  sulphide  A substance formed by uniting one ELEMENT or group with S a SALT of H2S (hydrogen sulphide or hydrosulphuric acid).   Go back