Robust control of a cell micro-manipulation system with IPMC actuators

A precise and robust controller has been developed and implemented on a novel ionic polymer-metal composite (IPMC) actuated micro-manipulator to demonstrate its ability to enable safe and reliable manipulation of biological cells. A 2 degree-of-freedom (2DOF) control structure was employed to enable the system to be optimised for both the disturbance response (DR) and set-point (SP) tracking. The controller is adaptively tuned using a model-free iterative feedback tuning (IFT) approach which is ideal for operation in unknown cellular environments and handling the time-varying behaviour of the IPMCs themselves. IFT experiments have tuned the IPMCs to an 87% and 81% performance improvement in DR and SP respectively. Experiments then reveal that the tuned controller has equipped the manipulator with an accuracy of <7.1% of full scale, with up to 7° of motion in both axes. The controller has also demonstrated its ability to naturally cope with load disturbances up to 10 mN.