Gut reaction

Chemists in Japan have demonstrated that the oscillating Belousov-Zhabotinsky reaction can be exploited to push a cargo along a length of smart polymer tubing in a process not unlike the peristaltic contractions of the intestine. Yusuke Shiraki and Ryo Yoshida of the University of Tokyo incorporated the ruthenium catalyst of the B-Z reaction into an N-isopropylacrylamide polymer gel to mimic peristalsis. The oscillating reaction starts up when this material is added to a solution of malonic acid, sodium bromate and nitric acid. The team has been developing smart gels since the 1990s, but the directional pumping of this chemical system might now have potential in "powering" microelectromechanical systems (MEMS) or driving reagents and analytes around a lab-on-a-chip.