Hybrid Pseudo-Resonant Switched-Capacitor Drive Circuits for Electrostatic Micro-mechanical Actuators

近几十年来，各种用于便携式消费、工业和医疗应用的低功耗、小尺寸电子设备的增长和扩散。在许多情况下，这些平台需要用于传感器和执行器、机械化控制、机器人和人机接口的机电接口。包括压电器件、硅MEMs和介电弹性体在内的新型静电（电场驱动）微机电致动器显示出巨大的潜力，可以克服传统磁基电动机的严重尺寸和重量限制。然而，这些技术需要为相关的电子接口提供新的设计范例，这些接口必须提供高驱动电压（通常为100伏至低千伏），同时从低压（个位数电压范围）电源进行升压，并且必须在小尺寸（~1cm3）和重量（~1g）下保持高效。一个独特的考虑是静电器件在大多数情况下以电容为主。因此，关键的挑战包括以极小的尺寸提供高压双向DC-DC转换，同时在Hz-kHz范围内的驱动频率有效地提供（和恢复）无功功率。解决这些挑战可能会对医疗和生物医学设备、微流体、成像、光学和通信、超声波和触觉触觉界面等多个行业产生影响。该项目将涉及探索、设计和集成用于静电微机械执行器的高效、高压、毫米级驱动电子器件。将开发一种新的混合伪谐振结构，该结构将可重构串并联开关电容（SC）变换器与基于低压双向电感的DC-DC变换器相结合。这种混合方法融合了纯SC和基于电感的拓扑结构的优点，同时提供了恢复（再循环）存储在致动器体电介质中的能量的能力。该方案的智力优势包括电路技术、控制和通信概念，可以提供显著的优势——扩展电压转换范围，提供稳定的调节，消除设计权衡，与传统架构相比，将总功耗降低一个数量级以上。该项目将包括对结构细节的研究，包括混合转换器各部分的电流、电压和额定功率的最佳分割，以最大限度地提高总尺寸为100mm3、重量为100mg时的性能。将开发一种新的、高度可扩展的电平转换策略，以实现芯片串联堆叠，使驱动电压远远超过半导体埋地氧化物（BOX）击穿限制。集成电路（IC）原型将设计300V SOI CMOS工艺，以演示高压操作，执行器能量回收以及从1.7-4.2 V电源到低kv驱动电压的芯片堆叠。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Recent decades have seen the growth and proliferation of a variety of low-power, small-size electronic devices for portable consumer, industrial, and medical applications. In many cases these platforms desire electromechanical interfaces for sensors and actuators, mechanized control, robotics, and human-machine interfaces. New electrostatic (electric-field-driven) micro-electromechanical actuators including piezoelectric devices, silicon MEMs, and dielectric elastomers show significant potential to overcome the severe size and weight limitations of conventional magnetic-based electric motors. However, these technologies require new design paradigms for the associated electronic interfaces, which must provide high driving voltages (typically 100’s of volts to low kV) while boosting from low-voltage (single-digit volt range) supplies, and must remain efficient at small size (~1cm3) and weight (~1g). A unique consideration is that electrostatic devices present as dominantly capacitive in most scenarios. Therefore key challenges include providing high-voltage bidirectional DC-DC conversion at extremely small size, while efficiently delivering (and recovering) reactive power at drive frequencies in a Hz-kHz range. Addressing these challenges could have impacts in diverse industry sectors from medical and biomedical devices, microfluidics, imaging, optics and communications, ultrasound, and haptic tactile interfaces.This project will involve the exploration, design, and integration of efficient, high-voltage, mm-scale drive electronics for electrostatic micro-mechanical actuators. A new hybrid pseudo-resonant architecture will be developed that merges a reconfigurable series-parallel switched capacitor (SC) converter with a low-voltage bidirectional inductor-based DC-DC converter. The hybrid approach merges the advantages of pure SC and inductor-based topologies while providing capabilities to recover (recycle) energy stored in the actuator bulk dielectric. The intellectual merit of the proposal includes circuit techniques, control, and communication concepts that can provide significant advantages – extending the voltage conversion range, providing stable regulation, eliminating design tradeoffs, and reducing overall power loss by over an order of magnitude compared to conventional architectures. The project will include the study of architecture details including optimal segmentation of current, voltage, and power ratings of the respective portions of the hybrid converter to maximize performance at total size 100mm3 and weight 100mg. A new, highly-scalable, level-shifting strategy will be developed to enable chip-chip series stacking, allowing drive voltages well in excess of the semiconductor buried-oxide (BOX) breakdown limit. An integrated circuit (IC) prototype will be designed a 300V SOI CMOS process to demonstrate high-voltage operation, actuator energy recovery, and chip-chip stacking to low-kV drive voltages from 1.7-4.2 V supplies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.