Authors: J. Kao, J. Warren, J. Xu and D. Attinger
Affilation: Columbia University, United States
Pages: 332 - 335
Keywords: rotor, actuator, micro-bubble, acoustic streaming, micro-machine
We present and characterize a novel micro-rotor actuation concept, where acoustic oscillations of a micro-bubble produce a steady fluid flow driving a microfabricated rotor at a rotating speed as high as 600 rpm. <br>Developing micro-machines can be done in two ways. A first approach it to miniaturize an existing macroscopic solution, as successfully exemplified by the micro-gas turbine of Frechette et al. (ref.1 ). Another approach is to take advantage of the different ratio of forces on the microscale, as exemplified by the bubble-jet printing technology, where the explosive growth of a bubble acts as a piston (ref. 2). This second approach can lead to simpler designs, with fewer issues of geometric tolerances. Our goal is to use this second approach to generate controllable rotary power in a package as thin as a human hair.<br>Besides proving the feasibility of this novel rotor actuation concept, our study provides basic experimental data for modeling the complex interaction between the fluid flow and the rotor, with the objective to develop rotors with optimized shape. Finally, we outline construction steps to develop this micro-rotor into a micro-motor delivering a controllable and infinitesimal power on the microscale.