According to a report from the University of Southern Denmark, scientists have made simple droplets of alcohol move on their own through water. Future technological applications based on this finding may allow for the delivery of medicines, and other applications.
“The system itself is very simple but yet it displays sophisticated behavior”, explains principal investigator Martin Hanczyc, who was at Center for Fundamental Living Technology (FLINT), University of Southern Denmark, when the research was completed.
Video of the experiment can be seen here.
Hanczyc and his colleagues from Institute of Chemical Technology in Prague have shown that small droplets of alcohol in water can move through complex mazes. The droplets can be led to certain targets, and therefore they may be used as a technology to physically move chemistry to a place where it is desired.
“For example, the droplet can act either as a lubricant, targeting an area that needs lubrication. Or the droplet can act as a carrier for chemistry that can find a target destination and release its content, such as flavoring, medicine etc.,” Hanczyc explained.
The droplets began to move when they sense salt in their environment.
“Salt is the stimulus that makes them move. They move because the salt gradient provides a different energy landscape. It is like taking a ball that is laying still on a flat surface and then suddenly make the surface hilly. The ball will roll to the lowest accessible point. That is what the droplet is doing. Without a salt gradient every direction in which a droplet might move looks the same (flat). But with a salt gradient coming from one direction the droplet can move energetically downhill into the salt gradient. And stronger salt concentrations will attract the droplet more,” said Hanczyc.
The system is sustainable in that the same droplet can travel towards salts at different positions added in succession. Additionally, the droplet can distinguish between salt sources of different concentration. The process can be controlled by external temperature stimulus, and when the droplet reaches the source it can physically fuse with it and react with it.