UT Austin, NSF REU
MEMS comb drive actuator
Electrostatic actuator for mechanical neural networks
- Program
- NSF REU
- Lab
- Nanoscale Design and Manufacturing Laboratory
- Tools
- MATLAB, ANSYS, SolidWorks
- Trade-offs
- Force, displacement, natural frequency
Overview
The question and my part
The question
A comb drive is an electrostatic MEMS actuator: two sets of interlocking fingers, one fixed and one on a spring-suspended shuttle, pull together when a voltage is applied. The lab uses these actuators in mechanical neural networks.
My project looked at how the actuator's design parameters trade off three things that pull against each other: force, displacement and natural frequency.
My part
From June to August 2025 I was an NSF REU research intern in the Nanoscale Design and Manufacturing Laboratory at UT Austin, working with Dr. Michael Cullinan and Andrew Gray. I built the analytical model, ran the parameter sweeps and ANSYS simulations, and used the results to refine the actuator geometry in SolidWorks.
Method
From model to geometry
Analytical model
MATLAB
Wrote an analytical model to predict how force, displacement and natural frequency change with the design parameters.
Parameter sweeps
MATLAB
Swept the parameters and plotted the results to find designs that maximize both displacement and electrostatic force.
Simulation
ANSYS
Ran ANSYS simulations to evaluate the same design trade-offs.
CAD refinement
SolidWorks
Refined the actuator geometry so it stayed compatible with the lab's fabrication constraints.
Takeaways
What I learned
The main thing I took away was how to turn a theoretical model into design decisions, balancing performance goals against real-world limits such as what the lab can fabricate.
I also saw the research process from end to end: from early-stage modeling to designs that are ready to move toward real-world use.
Where
The lab
The Nanoscale Design and Manufacturing Laboratory is part of the Walker Department of Mechanical Engineering at The University of Texas at Austin. I spent the summer there through the National Science Foundation's Research Experiences for Undergraduates (REU) program.