invaderxan: Like rats, oil drops can navigate mazes too: Scientists have found a way to make simple droplets of oil navigate complex labyrinths with the same skill as laboratory rodents. The advance could help researchers devise better ways to solve other mazelike problems, from rooting out cancer in the body to mapping paths through traffic jams. Physical chemist Bartosz Grzybowski of Northwestern University in Evanston, Illinois, and colleagues hit upon the droplets while trying to devise novel cancer therapies. Scientists have developed a variety of ways to get cancer drugs into the body - including nanoparticles and liposomes - but all face the same obstacle: It’s hard to navigate the body’s maze of vessels and tissues to seek out and destroy hidden cancers. So Grzybowski’s team made a number of silicon mazes roughly 6.5 square centimeters in size. To create the conditions for movement, the researchers filled the labyrinths with an alkaline solution of potassium hydroxide. The maze runners, placed at the entrance of the labyrinths, were millimeter-wide droplets of either mineral oil or the organic solvent dichloromethane, both loaded with a weak acid and red dye. The “prize,” placed at the exit of each maze, was a lump of agarose gel soaked in hydrochloric acid. “We wanted to give [the droplets] a bit of a challenge and see if they could do more than just go in a straight line,” Grzybowski says. Over the course of a minute or so, each droplet found its way to the end of the maze. The reason they move in the right direction has to do with basic chemistry. 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 droplets always found the shortest possible paths through the maze. (via maxistentialist)

invaderxan:

Like rats, oil drops can navigate mazes too:

Scientists have found a way to make simple droplets of oil navigate complex labyrinths with the same skill as laboratory rodents. The advance could help researchers devise better ways to solve other mazelike problems, from rooting out cancer in the body to mapping paths through traffic jams.

Physical chemist Bartosz Grzybowski of Northwestern University in Evanston, Illinois, and colleagues hit upon the droplets while trying to devise novel cancer therapies. Scientists have developed a variety of ways to get cancer drugs into the body - including nanoparticles and liposomes - but all face the same obstacle: It’s hard to navigate the body’s maze of vessels and tissues to seek out and destroy hidden cancers.

So Grzybowski’s team made a number of silicon mazes roughly 6.5 square centimeters in size. To create the conditions for movement, the researchers filled the labyrinths with an alkaline solution of potassium hydroxide. The maze runners, placed at the entrance of the labyrinths, were millimeter-wide droplets of either mineral oil or the organic solvent dichloromethane, both loaded with a weak acid and red dye. The “prize,” placed at the exit of each maze, was a lump of agarose gel soaked in hydrochloric acid. “We wanted to give [the droplets] a bit of a challenge and see if they could do more than just go in a straight line,” Grzybowski says.

Over the course of a minute or so, each droplet found its way to the end of the maze. The reason they move in the right direction has to do with basic chemistry. 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 droplets always found the shortest possible paths through the maze.

(via maxistentialist)