An adaptive impedance force control approach for robotic cell microinjection

Robotic cell microinjection is a technique that employs an automatic method to insert substances into a single living cell with a fine needle. Most available microinjection methods are based on position/velocity tracking, which make it incapable of controlling the injection force. The uncontrolled injection force, however, may destroy the cell and lead to the death of the cell. In this paper, a new adaptive force tracking algorithm within the impedance control framework is proposed to control the injection force applied on the cell. A target impedance is specified in the inner-loop and a trajectory modifying controller is design in the outer-loop for time varying ramp force tracking. The adaptive technique is also used to compensate for the uncertainty of the cell membrane's stiffness, the convergence of the system is provably guaranteed. Experiments performed on a laboratorial robotic cell injection system demonstrate the effectiveness of the approach.