A Miniaturized Platform for a Modular High-Voltage Electrostatic Actuator Driver

High voltage drivers are needed for electrostatic and piezoelectric actuators in small-scale electromechanical systems such as microrobotics and haptics. This paper presents a miniaturized platform for a modular switched-capacitor-based driver, implemented in a 180nm HV-SOI CMOS integrated circuit (IC), that uses less than 5 $\mu$A quiescent current per chip and includes an auxiliary (magnetic) boost converter to interface with low-voltage (~2.5-3.7V) batteries. The platform allows multiple PCB modules to stack in series voltage domains, extending drive voltages to the kilovolt-range, beyond the process and buried-oxide (BOX) limits of a single chip. Compared to past work with the same IC [1], the improved platform achieves >100$\times$ volume reduction and >30$\times$ weight reduction; with eight boards stacked, the system can provide peak-peak drive voltages up to 3 kV from a 3.7V supply (voltage conversion ratios VCR >800), delivering and recovering ~1W reactive power with over 97% efficiency.