Molecular Cars That Drive Over Obstacles And Under Microscopes

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Molecular cars here refer to small microscopic nanocars that were recently developed by some scientists from North Carolina State University and Rice University. These are basically complex molecules that can move from one place to another with the help of stimulants and light. Prior to this, nanocars were tested only within the confines of vacuum chambers, but this group of scientists decided to get these out of there and give them some real moves. Before any automobile company tries to take it over assembly lines, it should be known to all that the concept is currently under rigorous testing in labs as well as on actual roads. The makers are still testing its response to rains, storms, temperature fluctuations, roads filled with potholes, road bumps, and other obstacles.

What motivated them to go deep in this concept is the close resemblance of these molecules with actual car chassis and their ability to transport small scale payloads from one place to another. Microscopic vehicles like these can play a crucial role in medical and computer world. Imagine small molecules carrying medicine in your body to the required organs or manufacturing new variety of computer circuits. As James Tour, a scientist from the Rice University likes to add, “Our long-term goal is to make nanomachines that operate in ambient environments. That’s when they will show potential to become useful tools for medicines and bottom-up manufacturing.”

The semiconductor industry is also showing deep interest in this concept and has been making studies to find if these can be used in computer circuit production on a molecular level. It would be different from the up-down approach that implies etching of transistors directly over chips by engineers. The inverse, bottom-up approach, would include coalescing of molecules in the circuits where nanocars would act like enzymes adding extra parts.

The latest version of these complex molecules was laced with wheels that were formed from adamantine. The wheels are, by nature, little water repellent which helps them in sticking with the surface properly. Hydrophobic molecules tend to stick together closely in order to minimize their overall contact with water surface. But the hydrophobic nature of these molecules needs to be restricted to a certain limit, if it exceeds that the molecules will stick to the surface permanently.

The team of scientists working on it actually tested the cars over glass substrate that is usually used for nanomachine research purposes. Two different tracks were used, one was coated with special polymer (non-sticky properties) and the other one was cleaned with hydrogen peroxide to help in movement of wheels. The difference in these two surfaces played crucial role in demonstration of nanocars movement. As Tour further likes to add, “We want to know what makes a nanocar ‘hit the bakes’ and how much external energy we need to apply to start it moving again.” The movement of all these machines was tracked under microscopes with the help of fluorescent tags. Road conditions were difficult when it came to driving of nanocars. The glass surface absorbed air molecules that filled the track with microscopic puddles and bumps. The nanocars have singular molecular structures that cannot move over obstacles in the path leading to their permanent immobility over such tracks. But when the glass surface was coated with a special polymer, polyethylene glycol, the cars were able to perform better and they could move at a speed of 0.0006 inches per hour.