Monday, November 1, 2010

All Electric Single Molecule Motor






I do not know what this creation could be used for, but it certainly demonstrates design possibilities at the molecular level only imagined before as possible.  The real measure of this methodology will be the creation of useful products.


It is still pretty exciting and certainly will be neat to see demonstrated if it can be.

However, this demonstrates a high level of sophistication arriving in the area of nano sized mechanical structures.  The actual strength of such structures can be orders of magnitude relative to macrostructeral designs that we are used to so expanded application are plausible.

How about pumps that never wears out and is driven by chemistry?



OCTOBER 28, 2010



Many types of molecular motors have been proposed and synthesized in recent years, displaying different kinds of motion, and fueled by different driving forces such as light, heat, or chemical reactions. We propose a new type of molecular motor based on electric field actuation and electric current detection of the rotational motion of a molecular dipole embedded in a three-terminal single-molecule device. The key aspect of this all-electronic design is the conjugated backbone of the molecule, which simultaneously provides the potential landscape of the rotor orientation and a real-time measure of that orientation through the modulation of the conductivity. Using quantum chemistry calculations, we show that this approach provides full control over the speed and continuity of motion, thereby combining electrical and mechanical control at the molecular level over a wide range of temperatures. Moreover, chemistry can be used to change all key parameters of the device, enabling a variety of new experiments on molecular motors.

The motor's rotor is a long, coal-derived molecule called anthracene, which spins around an axle composed of two ethynyl units. Each end of this axle is connected to an electrode, and a third electrode – called the gate – is located slightly below the axle.

Applying an alternating current to this gate electrode sets up an oscillating electric field that surrounds the molecular motor and, according to the researchers' calculations, should cause the anthracene rotor to turn.

That's because anthracene possesses what is known as a dipole moment – its negatively charged electrons tend to congregate at one end of the molecule, making the other end positively charged.

No comments: