Forcing a molecule's hand : ultrasound can be used to control molecular processes as delicate as rotation around a single carbon–carbon bond

Ultrasound can be used to control molecular processes as delicate as rotation around a single carbon–carbon bond. 'Tug of War' is a game that tests the strength of two teams pulling on a rope in opposite directions. If it is being played on a molecular scale, the game is known as polymer mechanochemistry, and the interest is not so much in the muscle power of the contestants as in the strength of the rope and its fate under stress.