A group of scientists have created a new synthesized particle in the laboratory that is able to act in a lifelike way. The researchers are quick to say that particles aren’t truly alive, but they are able to behave in lifelike ways when exposed to light and fed by chemicals. When exposed to light and fed by chemicals the crystals are able to move, clump together, break apart, and reform.
Biophysicist Jérémie Palacci of New York University says that the line between active and alive is very blurry. Palacci and another New York University physicist Paul Chaikin are leading a group of researchers to develop the particles described as “living crystals” under the right conditions. The research being conducted by the team is in self-organizing collective behaviors.
The researchers say that studying these collective behaviors is easier in a controlled particle form than trying to study living creature such as schooling fish or flocking birds. Each of the tiny crystals is made from a cube of hematite, which is a compound made of iron and oxygen, covered in a spherical polymer coat. One corner of the hematite is left exposed.
When the particle is exposed to certain wavelengths of blue light, the hematite is able to conduct electricity. When those particles are placed in a hydrogen peroxide bath and the correct wavelength of blue light is shined on them, chemical reactions catalyze around the single exposed tip. Then as the hydrogen peroxide breaks down, the scientists say concentration gradients form. Random forces then pull the crystals apart, but the crystals eventually merge again. This process doesn’t stop until the blue light is turned off.