Catalytic Nanoshell Micromotors

Combining conventional physical vapor deposition and wet chemical etching, nanoshell catalytic motors with catalyst coated inside the shell have been fabricated. Those motors are propelled by bubble ejection or burst mechanism due to small bubble nucleation energy, and they move much faster than the Janus catalytic motors of the same size. The speeds of the motors (similar to 100 mu m s(-1)) are closely related to the bubble size and generation frequency. The experimental data show that the bubbles do not totally block the opening of the shell and, thus, achieve a fast mass transport and sustain continuous motion of the motors.