Electrostatic micro-actuator with a pre-charged series capacitor: modeling, design, and demonstration

Abstract

As a powerful method to reduce actuation voltage in an electrostatic micro-actuator, we propose and investigate an electrostatic micro-actuator with a pre-charged series capacitor. In contrast to a conventional electrostatic actuator, the injected pre-charges into the series capacitor can freely modulate the pull-in voltage of the proposed actuator even after the completion of fabrication. The static characteristics of the proposed actuator were investigated by first developing analytical models based on a parallel-plate capacitor model. We then successfully designed and demonstrated a micro-switch with a pre-charged series capacitor. The pull-in voltage of the fabricated micro-switch was reduced from 65.4 to 0.6 V when pre-charged with 46.3 V. The on-resistance of the fabricated micro-switch was almost the same as the initial one, even when the device was pre-charged, which was demonstrated for the first time. All results from the analytical models, finite element method simulations, and measurements were in good agreement with deviations of less than 10%. This work can be favorably adapted to electrostatic micro-switches which need a low actuation voltage without noticeable degradation of performance.

Microparticle Manipulation Based on the Bulk Acoustic Wave Combined with the Liquid Crystal Backflow Effect Driving in 2D/3D Platforms

“… 33 As aforementioned, acoustic microfluidic methods can be integrated with other microfluidic designs for enhanced fluid and particle manipulation performance. 34 − 36 For example, Huang et al. achieved dynamic manipulation of micro-objects by combining hydrodynamic manipulation and acoustic microfluidic manipulation.…”

“…Zhao et al demonstrated the pumping of water droplets based on capillary force and developed and employed structural color micromotors (SCMs) that could realize multiplex label-free detection of ions based on their optical coding capacity and responsive behaviors . As aforementioned, acoustic microfluidic methods can be integrated with other microfluidic designs for enhanced fluid and particle manipulation performance. − For example, Huang et al. achieved dynamic manipulation of micro-objects by combining hydrodynamic manipulation and acoustic microfluidic manipulation. − They developed acoustic circulating tumor cell (CTC) separation devices integrating hydrodynamics and IDT and isolated rare CTCs from peripheral blood in a single direction; Zhou et al presented a rapid and powerful method to size dependently control movement of microparticles and cells in paper using surface acoustic waves by combining paper-based microfluidics with acoustics .…”