Generation of swirl flow by needle vibration for micro manipulation

Recently micro manipulation techniques for cell or microorganism has attracted attention in life sciences. In this paper, non-contact manipulation method using water stream is proposed. Water stream is generated by a glass needle vibration that is actuated by a piezoelectric actuator. The stream is controlled by changing input voltage or frequency to the actuator. An accuracy of the motion of a piezoelectric actuator is in nano-meter order, so the stream is considered to be controlled precisely. The manipulator works in 3 dimensional space, that means water stream is generated in 3d space. We focused on the rotational stream generated by the glass needle 2-dimensional circular vibration. By using the resonance in a structure of the manipulator and the actuator´s vibration, circular vibration can be generated by only one actuator. There is no need to use two actuators for generating circular vibration, so the structure of the manipulator is quite simple. In this paper rotational stream around the glass needle is also analyzed in 3d space using micro beads. This manipulator has the similar characteristics to the existing research of contact manipulation, so we think our method also have the capability to conduct contact manipulation.