Inversion-based feedforward control of polypyrrole trilayer bender actuators

Conducting polymer bending actuators show potential for unique manipulation devices, particularly at the microscale, given low actuation voltages, controllable manufacture, biocompatibility, and ability to operate in either air or liquid environments; however, the impracticalities of implementing feedback in these environments and at these scales can impede positional control of the actuator. This paper presents an application of inversion-based feedforward positional control to a trilayer bender actuator, which is shown to improve the performance without the use of feedback or adjustments to the chemistry of the device. The step and dynamic displacement responses have all been improved under the feedforward control system, while the response does not change significantly under large increases in external loads. This study contributes the first implementation of inversion-based feedforward control to the emerging area of conducting polymer actuators, paving the way toward their use in functional devices, particularly where the implementation of feedback is difficult.