rootninja

Scientists have figured out how to make a drop of oil navigate a complex maze. The oil can navigate a maze similar to a lab rat.

The secret is the labyrinth is filled with an alkaline solution of potassium hydroxide ( KOH). Millimeter-wide drops of mineral oil or dichloromethane (CH2CL2) are placed at the starting point in the maze while a piece of agarose gel (polysaccharide, like red bean foods) soaked in hydrochloric acid (HCl) is placed at the end.

Obviously, lab rats weren’t navigating the maze since it was filled with drain cleaner! (Most toilet bowl liquid drain cleaners contain a mixture of KOH and NaOH used to dissolve deposits, hairballs, or the freaking skin on your hands)

Acid from the highly acidic gel slowly leaks into the potassium hydroxide solution that fills the maze, creating a gradient: Solution near the exit becomes more acidic, whereas solution near the entrance stays more basic. This basic solution interacts with the acidic droplet, causing the part of the droplet facing the exit to become more acidic than the part of the droplet facing away from the exit. The disparity increases the surface tension of the side of the droplet that faces the exit–and it’s this difference in surface tension between the two sides of the droplet that propels it toward the exit of the maze.

The mineral oil always found the shortest path from start to finish. The methylene chloride traveled faster but made more wrong turns. The work could prove beneficial in converting several areas:

* Converting chemical energy into motion in small fluid filled devices
* Traffic congestion systems
* Medicine (drug delivery, cancer killers)

I would show the molecular structure of mineral oil here, but it comes in so many forms…