Demonstrating the Potential of a Novel Model to Improve Open-Loop Control of Electrostatic Comb-Drive Actuators in Electrolytes

Author(s):  
Ohiremen Dibua ◽  
Vikram Mukundan ◽  
Beth Pruitt ◽  
Ali Mani ◽  
Gianluca Iaccarino

Electrostatic comb-drive actuators in electrolytes have many potential applications, including characterizing biological structures. Maximizing the utility of these devices for such applications requires a model capable of accurately predicting their behavior over both micron and submicron scales of displacement. Classic circuit models of these systems assume that the native oxide is a pure dielectric, and that the ion concentration of the bulk electrolyte is constant. We propose augmented models that separately address these assumptions, and analyze their ability to predict the displacement of the electrostatic actuators in electrolytic solutions. We find that the model which removes the assumption that the native oxide is a pure dielectric most accurately predicts comb-drive actuator behavior in electrolytes.

Author(s):  
I. P. M. Wickramasinghe ◽  
Jordan M. Berg

The stable operating region of an electrostatic comb drive actuator in constant-gap mode is limited by a subcritical pitch-fork bifurcation known as side pull-in. We show that oscillatory open-loop control can forestall side pull-in and substantially extend the stable operating region. To our knowledge, this is the first demonstration of control of side pull-in without additional lateral actuators. To our knowledge it is also the first application of open-loop oscillatory control to an electrostatic MEMS model using a single control voltage. Simulations show the stable range of travel increased by over 60%, with an associated oscillation of less than 2%. Although feedback control has been used to stabilize a related bifurcation in electrostatic gap-closing actuators, we show that these approaches are unlikely to succeed for side pull-in. Finally, we present and validate formulas relating parameters of the oscillatory input to the average value and oscillations of the resulting displacement.


1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen

2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf

2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.


2002 ◽  
Vol 21 (10-11) ◽  
pp. 849-859 ◽  
Author(s):  
Kenneth A. Mcisaac ◽  
James P. Ostrowski

In this paper, we describe experimental work using an underwater, biomimetic, eel-like robot to verify a simplified dynamic model and open-loop control routines. We compare experimental results to previous analytically derived, but approximate expressions for proposed gaits for forward/backward swimming, circular swimming, sideways swimming and turning in place. We have developed a five-link, underwater eel-like robot, focusing on modularity, reliability and rapid prototyping, to verify our theoretical predictions. Results from open-loop experiments performed with this robot in an aquatic environment using an off-line vision system for position sensing show good agreement with theory.


AIAA Journal ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Ellen K. Longmire ◽  
John K. Eaton

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