Now there is a "microrocket" that uses acid as a fuel.
(PhysOrg.com) -- Recently, researchers have been designing a wide variety of self-propelled micromotors, many of which operate using an oxygen-bubble propulsion mechanism that requires a high concentration of hydrogen peroxide fuel. Since hydrogen peroxide is hazardous at high concentrations, this requirement has hindered practical applications, especially biomedical uses. Now in a new study, scientists have designed and built a new type of micromotor that propels itself through acidic environments with hydrogen bubbles, and requires no additional fuels. At extremely low pH levels, the micromotors can travel at speeds of up to 100 body lengths per second, prompting the scientists to call them “microrockets.”
The researchers, Wei Gao, Aysegul Uygun, and Joseph Wang from the University of California, San Diego, have published their study on the hydrogen-bubble-propelled microrockets in a recent issue of the Journal of the American Chemical Society.
“This is the first reported example of chemically-powered microrockets that can be self-propelled without an external fuel (such as the common hydrogen peroxide),” Wang told PhysOrg.com. “Such acid-powered microrockets could greatly expand the scope of applications of nano-/microscale motors toward new extreme environments (e.g., the human stomach or silicon wet-etching baths) and could thus lead to diverse new biomedical or industrial applications ranging from targeted drug delivery or nanoimaging to the monitoring of industrial processes.”