Water-Driven Micromotors

Condensed Matter journal club

Water-Driven Micromotors

  • Event time: 11:30am
  • Event date: 2nd November 2012
  • Speaker: (School of Physics & Astronomy, University of Edinburgh)
  • Location: Room 2511,

Event details


We demonstrate the first example of a water-driven bubble-propelled micromotor that eliminates the requirement for the common hydrogen peroxide fuel. The new water-driven Janus micromotor is composed of a partially coated Al-Ga binary alloy microsphere prepared via microcontact mixing of aluminum microparticles and liquid gallium. The ejection of hydrogen bubbles from the exposed Al-Ga alloy hemisphere side, upon its contact with water, provides a powerful directional propulsion thrust. Such spontaneous generation of hydrogen bubbles reflects the rapid reaction between the aluminum alloy and water. The resulting water-driven spherical motors can move at remarkable speeds of 3 mm s-1 (i.e., 150 body length s-1), while exerting large forces exceeding 500 pN. Factors influencing the efficiency of the aluminum-water reaction and the resulting propulsion behavior and motor lifetime, including the ionic strength and environmental pH, are investigated. The resulting water-propelled Al-Ga/Ti motors move efficiently in different biological media (e.g., human serum) and hold considerable promise for diverse biomedical or industrial applications.
ACS Nano 6 pages 8432-8438 (2012)
pdf version of paper


Wei Gao, Allen Pei, Joseph Wang