We have developed a highly functional untethered micro-robot that can manipulate cells with high gripping force in a micro-fluidic chip. The robot has gripping mechanism for grasping and transportation of cells with sufficient power. A permanent magnet is attached at the center of the gripping mechanism, and an electrical magnet controls the position of the magnet from the bottom of the micro-fluidic chip. The distance accuracy of the gripper is 3.0 μm, and it can activate about 50 Hz. The robot has four permanent magnets for positioning, and other four permanent magnets control the robot from the bottom of the micro-fluidic chip. The robot is made very thin and small to allow maneuverability in a micro-fluidic chip. We succeeded in high-power handling and cutting of a cell using this micro-robot.

We have successfully produced mono-dispersed micro-gas bubbles for less than around 10 μm diameter by micro-bubble knife which produce micro-bubble in an electrically induced ultrasonic field. The discharged output power and conductive area of micro-electrode in micro-bubble knife which cuts the cell by micro-bubble were controlled by glass shell insulation around the copper micro-wire. A small space which is called “bubble reservoir” between the wire and glass tip contributes to stabilize the electric discharge and directional bubble generation. The directionally dispensed bubbles can be used for processing of soft materials such as biological cells. For the present study the cell membrane has successfully processed with a few μm order resolution.