These “xenobots” are living machines designed by an evolutionary algorithm

Tiny living robots have been created using cells taken from frog embryos. Each so-called xenobot is less than a millimeter across, but one can propel itself through water using two stumpy limbs, while another has a kind of pouch that it could use to carry a small load. 

https://www.technologyreview.com/f/615041/these-xenobots-are-living-machines-designed-by-an-evolutionary-algorithm/