Bimetallic micromotor autonomously movable in biofuels

Zinc/platinum (Zn/Pt) bimetallic micromotors have been developed. They moved based on the reduction of fuel compounds such as bromine, p-benzoquinone, and methanol at the surface of the Pt and the oxidation (dissolution) of Zn that occur simultaneously. The redox potential of Zn²⁺/Zn is very negative and was advantageous to cause the redox reactions. The motion of the motor and the reactions that occurred on the surface were investigated. With test motors containing Ni, it was revealed that the Zn/Pt motors showed almost unidirectional motion to the Zn side. Toxicity of Zn²⁺ is relatively lower than that of other metal ions. Also, the motor features the use of mild compounds such as methanol that are not harmful to tissues or organisms as their fuels.