The Research Problem
• In one microactuator concept,
bubbles of gas are formed at a
Platinum Electrode.
• Bubbles sticking to the
electrode are expected to be a
problem.
• How can we get rid of
bubbles?
A Possible Solution
• Inducing vibrations, mechanically or
electromagnetically, is a possible solution.
• Resonant excitation is the most efficient
technique to achieve large accelerations at
the electrode surface.
• What are the resonant modes and
associated frequencies? FEM to the
rescue.
Solution Process
• COMSOL Simulation
Environment
• Undamped
Eigenfrequency
Analysis
• Pt electrode was
modeled as a helix
with a single fixed
endpoint.
Eigenfrequency Analysis Results
Electrode Parameters
• Pure Pt Wire
• 24AWG (F0.50mm)
• Helix has centerline
diameter F1.90mm
• 38 Revolutions
• Length 26.1mm
• One fixed end, one
free end
Mode Frequency (Hz)
1
2
20.894 20.913
3
4
129.86 129.96
5
6
7
8
9
353.47
358.83 360.11
392.83
10 690.37 690.62
Normal Modes
1 and 2
Normal Modes
3 and 4
Normal Mode
5
Normal Mode
8
Close Eigenstates