A Drive–Vibration Integrated Piezoelectric Actuator for Flexible Electrode Implantation

In this paper, a drive-vibration integrated piezoelectric actuator (DVIPA) is proposed for vibration-assisted implantation of flexible electrodes. Conventional implantation systems typically rely on separate actuation and vibration modules, which increase system complexity and limit integration. To address this limitation, the proposed DVIPA integrates driving and vibration functions within a single compact structure by employing two piezoelectric bimorphs for clamping and a piezoelectric stack for combined actuation. A composite excitation waveform, consisting of high-frequency sinusoidal signals superimposed on the rising stage of a low-frequency trapezoidal wave, is applied to simultaneously generate forward motion and vibration. This configuration enables a coupled motion mode that facilitates insertion while reducing the risk of buckling. A prototype of the DVIPA was developed and experimentally evaluated. The results show that vibration-assisted implantation can be achieved under various operating conditions, with independently adjustable driving and vibration parameters. A maximum speed of 328 μm/s is obtained, meeting the requirements for flexible electrode implantation. Agarose gel experiments further demonstrate that vibration frequencies above 40 Hz and voltages between 20 and 40 V can effectively assist implantation of polydimethylsiloxane (PDMS) without buckling failure. Overall, the proposed actuator provides a compact and integrated solution for vibration-assisted implantation, offering potential advantages in applications with limited space.